Of the more than 300 corporate in-house counsel that The Texas Lawbook has honored and profiled over the past decade, none of their paths to the C-suite had anything to do with a divorce or family law practice. And definitely none that ended up in oil and gas commodities work.
Castleton Commodities International Counsel Helen Xiang breaks all those molds.
A student at Rice University in 2014 studying economics, Xiang took a year off to be an assistant at a Houston family law firm during the day and a small finance firm late in the afternoons.
“I found I enjoyed the legal work more and I could see myself in that role, of answering client questions and navigating them through complex situations, of presenting your client’s position and strategizing through arguments and negotiations, and of drawing on previous experience and applying them to a new fact pattern,” she told The Lawbook. “Family law can be messy, but the attorneys I worked for were so professional and unfazed no matter what came in the door. After that, I started preparing to take the LSAT and apply to law school.”
Xiang is now celebrating 18 months at Castleton, a global energy commodities merchant and infrastructure investor. A year and a half in, her new in-house position has been packed with major accomplishments, including a leading role in CCI’s transformational acquisition of Linden Variable Frequency Transformer in New York City, the revolutionary adoption of CCI’s artificial intelligence platform and becoming the executive leadership’s “go-to advisor” on the shifting landscapes involving tariffs, taxes and regulatory risks.
“In just a short time, Helen has made an immediate impact at CCI, supporting the gas and power trading desks and CCI’s asset-side businesses, advising on matters ranging from transactional risk allocation and counterparty contracts to disputes, tariffs and regulatory exposure,” said Sidley Austin partner Irv Rotter. “Each day presents a different set of issues requiring rapid risk assessment, commercial sensitivity and decisive guidance. Her law firm background — representing major public and private energy companies in multibillion-dollar M&A transactions — prepared her to manage aggressive deal flow, triage competing priorities and navigate complex stakeholder environments.”
The Association of Corporate Counsel’s Houston Chapter and The Texas Lawbook are honoring Xiang with the 2026 Houston Corporate Counsel Award for Rookie of the Year, which recognizes lawyers who have been in-house counsel for two years or less.
“The Rookie of the Year Award is intended to recognize lawyers who, in a short time, demonstrate outsized influence and leadership,” said Rotter, who nominated Xiang for the award. “Helen Xiang has done precisely that. She has elevated the role of in-house counsel from legal advisor to strategic architect — helping shape how a global energy merchant manages risk, deploys capital and innovates responsibly in rapidly evolving markets.”
Xiang distinguished herself in 2025 “as a forward-thinking leader in innovative and responsible AI adoption” by working with her Castleton colleagues to develop internal protocols governing the use of the firm’s AI tool, which reviews materials subject to confidentiality agreements.
“This initiative required balancing innovation with legal and compliance safeguards — an especially delicate task in a data-driven trading and investment environment,” Rotter said. “Helen conducted meetings across teams and seniority levels to understand both technical functionality and user needs. She then developed practical guardrails and compliance procedures that allowed the principal investments team to leverage AI for efficiency while maintaining contractual and regulatory integrity.”
Premium Subscriber Q&A: Helen Xiang discusses the traits she seeks in outside counsel, what outside counsel need to know when working with her and more.
Xiang joined CCI in December 2024 after practicing in the corporate M&A sections at Vinson & Elkins and White & Case in Houston for five years.
“One of the first projects I got pulled in on when I joined was becoming the tariff point person on the legal team, and to date I’ve done my best to stay on top of the news, provide updates to our GC and work with many of the other teams at CCI and outside counsel to respond to changes in law and jump quickly on the refund process,” she told The Lawbook. “Another success is working with our natural gas desk in handling force majeure notices, supply cuts and other communications during Winter Storm Fern. I had to work with our traders and operations teams to review agreements and understand our rights and give advice as to communications with customers and counterparties.”
Mingda Zhao, a partner at Skadden Arps in Houston who worked with Xiang at White & Case, said Xiang is “not afraid to ask questions” if she does not agree with decisions.
“Every corporate lawyer works hard; Helen works smart,” Zhao said. “She thinks through issues and items before doing the work so it is more targeted and effectively than work for work’s sake. She has been able to jump in on the trading side and adapt her skills acquired doing M&A transactions and quickly plug into the CCI team.”
Latham & Watkins partner David Owen, who has worked with Xiang on multiple high-profile transactions, said she is “adept at managing complex and fast-paced matters.”
“I have found that Helen’s diverse transactional skills, combined with her keen interpersonal skills, have allowed her to navigate that role expertly,” said Owen, who is a partner in New York. “Helen is keenly aware of when issues should be handled amongst the legal teams and when to raise issues to the commercial team. I have been extremely impressed by her ability to manage both teams in a manner that is most efficient and helpful to progress the transaction.”
Xiang was born in China and moved to the U.S. with her family when she was four years old. The family first lived in Auburn, Alabama, then Odessa, Texas, then Chesterfield, Missouri, and finally Evans, Georgia, where she attended high school.
“Whenever I rattle off this list of places, people always ask me why I moved around so much, and honestly, it was all for my dad’s work,” she said. “My dad was a chemical engineer who was, and is, driven and fearless in his decision-making — if he felt like he found a better opportunity, he would seize it and make the most out of it. My mom was a stay-at-home mom when I was younger and then worked as a data analyst.”
Her parents were both the first in their families to attend college, and Xiang was the first to go to law school.
“The first time I ever considered it was in high school, and I, like so many other lawyers in this well-trodden path before me, joined the debate team and just loved the process of researching, writing up arguments and competing,” she said. “Still, I wasn’t completely sure.”
Then came the semester working at the family law firm that solidified her decision about law school. But also confirmed that family law was not her future.
“There is a lot of emotion involved on every matter, and I am the type to feel the clients’ pain and frustrations quite personally,” she said. “You end up wanting what’s best for the client, both in terms of the legal proceedings and also in life, and feel very bad for them when things don’t go their way.”
While at the University of Texas School of Law, she split her 1L year in 2017 between Vinson & Elkins and Hogan Lovells, both in their Houston offices.
At V&E, Xiang was placed in the corporate transactional group. At Hogan Lovells, she worked with the litigation practice.
“I found myself drawn to the corporate work more,” she said. “I liked the pace of the transactions and the parts of the energy space I got to see — in 2017, it was a lot of renewable energy projects, fracking and international investment. And of course, it’s cliché to say, but I also liked the people that I worked with and found some really great mentors who influenced and shaped my career.”
Xiang said meeting her husband during college was life-changing. She was invited to a trivia night hosted by a student group at South Texas College of Law in Houston. She was placed on a team that included Hugo Hernández.
“We just hit it off right away, and he was incredibly supportive and helpful as I worked through my applications and went through law school,” she said. “Both of us were first generation lawyers, and he gave me a lot of advice and tips that helped set me on the right path as a 1L and 2L.”
Hernández graduated from STCL in 2015 and he joined Chevron as tax counsel last year.
Xiang said her time practicing M&A at V&E and White & Case “taught me how to slow down, break down complicated aspects of a purchase agreement into simple explanations, and truly advise clients as to key issues.”
The decision to go in-house — and to Castleton specifically — came after she and her husband had their daughter in 2023.
“The unpredictability of the work got a little hard to manage,” she said. “So, when the job opportunity from Castleton came by, I was thrilled. It had everything I was looking for in terms of still doing sophisticated, complex work in a rapidly moving industry, but it also gave me more time to be with my family and unplug during the weekends.”
Xiang said going in-house required her to “rework the way that I approach legal questions and think from broader coverage and time frame.”
“Deals can often be discrete projects that, once you’re done, outside counsel steps back and lets operations and business move forward,” she said. “But then in-house counsel is implementing that. So, I had to think through the longer-term impacts of decisions we were making.”
“When you’re outside counsel, your client is probably coming to you with ideas that they’ve already discussed internally and everyone has agreed to move forward on,” she said. “Now that I’m in house, I get involved in a lot of these conversations at a brainstorming or preliminary stage, and sometimes I have to be the one to nix ideas or spell out the risks, and it’s hard to be in the position of saying ‘no’ to something that people are excited about, or something people have put work into.”
Xiang said the other five lawyers on Castleton’s legal team have guided her through the transition. She said associate general counsel Craig Galligan has “taught me so much about the natural gas markets, power transactions and FERC regulations.”
In late 2025 and early 2026, Xiang applied her M&A experience to CCI’s acquisition of Linden VFT — a deal announced in February.
“I was involved from the start, from submitting our offer letter, marking up the purchase agreement, having calls with our internal teams and outside counsel to negotiate the deal, and then with many of our operations teams to onboard the new company,” she said. “We worked with Irv [Rotter] and the rest of the Sidley team very closely on this one, and I got most involved during the pre-closing period as we were working through regulatory approvals and closing documents.”
“I got a lot of exposure to our investments team on this deal because they’d regularly reach out to me with questions on interpretating different parts of the purchase agreement,” she said. “I also helped walk them through the rep and warranty insurance process and helped prepare them for the bringdown call.”
Rotter said Xiang played a critical role in getting the Linden VFT transaction across the finish line.
“Helen worked closely with outside counsel and internal stakeholders on this transaction, demonstrating her ability to bridge outside counsel strategy with internal business execution,” he said. “Her prior experience negotiating complex purchase agreements, joint ventures and energy-sector M&A transactions enabled her to engage substantively in deal structuring, diligence and risk allocation and allowed her to add strategic value informed by her experience and transactional rigor.”
Latham’s Owen said that Xiang has been “a key component of several large” Castleton divestitures.
“These transactions have had resulted in massive returns for Castleton and its investors,” Owen said. “Helen has been at the forefront of all recent matters on which I’ve worked with Castleton, including being involved in the drafting and negotiation of the definitive transaction documents in respect of such transactions. I have been most impressed with Helen’s ability to maintain a steady hand during extremely fast-paced and stressful moments during transactions. Helen’s unique ability to maintain focus on what matters most on transactions has helped get them over the finish line. She does not panic, but instead attacks tasks calmly and systematically until the broader transaction is ready to sign and close.”
Fun Facts: Helen Xiang
- Favorite book: East of Eden by John Steinbeck. I read this with a group of great friends during the pandemic, and we really lost ourselves in our discussions about the characters, their emotions and the stories across generations.
- Favorite movie: Vertigo by Alfred Hitchcock. First watched it for a film class at Rice and was drawn in by the intriguing story and meticulous filmmaking technique. The Museum of Fine Arts Houston screened a 70mm version from one of its collectors, and seeing the rich colors on film was incredible.
- Favorite drink: Hot chocolate.
- Favorite restaurant: Hui Lau Shan. My daughter and I always kick off the weekend by sharing a bowl of mango chewy ball dessert on Friday nights.
- Favorite all-time vacation: My bar trip, when my husband and I went to Greece and Italy for three weeks. Hiked Zeus’ Cave in Crete, stayed at an Italian castle in Bevilacqua and got to see Pope Francis in person in Vatican City. And so many art museums!
- Hero in life: My parents. I can’t imagine the challenges they faced, moving to a foreign country and starting a life there. They’re always there to give me advice and make me the best food whenever I need it.