A serial entrepreneur raised $17 million to build a Big Law alternative. Read the pitch deck.

Arceus combines a law firm with software. The bet is that in-house legal teams don't want another tool to manage; they want the work done faster.

  • Arceus combines a law firm staffed with attorneys with software built to speed up contract review.
  • A new fundraise brings the company's total funding to $17 million.
  • Arceus shared the pitch deck it used to raise the new round of funding.

Mac Liu isn't a lawyer, but he knows how to build a tech startup. The two-time founder is betting that edge will separate his new law firm from a crowded field of neofirms.

Liu's startup, Arceus, combines a law firm staffed by attorneys with software built to speed up contract review. The company says it can shrink the time it takes to review a standard agreement from days or weeks to a few hours. If a review takes more than eight hours, it's free.

On Thursday, Arceus said it raised new funding led by Greycroft, bringing its total funding to $17 million. Craft Ventures and South Park Commons also participated.

Before Arceus, Liu worked in tech roles at Robinhood and Anduril. He later started Vultron, which built software for defense contractors. Earlier this year, he sold the company to a govtech firm, pWin. In the deal, pWin took Vultron's customer base, and Liu kept the cash. He's now recycling that money into Arceus.

The model is similar to one popularized by Crosby, which builds software for its own lawyers, and was most recently valued at $400 million. The bet is that in-house legal teams don't want another tool to manage; they want the work done faster.

Rather than requiring customers to log into another platform, Arceus lets employees submit contracts for review directly from Slack. A virtual agent gathers context from systems such as Salesforce and HubSpot, as well as from past agreements, suggests changes, and then routes the matter to one of the firm's attorneys for final review.

Liu says he has tried to build Arceus less like a law firm and more like a startup. He hired engineers before his first lawyer. Employees work together in the office six days a week. Liu wants every customer request acknowledged within five minutes, though he said Arceus isn't there yet.

"You're not pinging a lawyer because you just want to chat," Liu said. "You're nervous about something, you're questioning something, and you want to feel like someone's there."

Some of the best-funded neofirms were started by in-house lawyers. Crosby founder Ryan Daniels previously worked as a fractional general counsel. Vector Legal's Mitch Duncombe was a lawyer at Y Combinator. Their own software reflects years spent doing the work.

Liu argues the real competition isn't other AI-native law firms. Instead, he sees the company taking share from three places at once: traditional law firms, in-house legal teams, and the software companies that sell tools to corporate lawyers.

Someday, he says, customers that hire Arceus may need fewer internal lawyers —a lofty goal at a time when most legal departments are still figuring out where AI belongs.

Investors, at least, are buying into that vision.

Read the pitch deck Arceus used to raise its Series A.

Arceus promotional graphic advertises a law firm for fast-growing companies beside a black-and-white dune image.

Presentation slide titled “Revenue, volume, and speed all increasing QoQ.” with key metrics, some values blacked out.

Presentation slide states law firms are slow, expensive, and unpredictable, listing turnaround, timeline, billing, and counsel issues.

Presentation slide compares traditional firms, AI software, and Arceus across turnaround, pricing, staffing, and margin.

Minimal presentation slide explains CounselOS context gathering and attorney review with integrations for Slack, Gmail, HubSpot, Salesforce, and Google Drive.

Minimal presentation slide explains how CounselOS helps a law firm remember business profiles, agreements, decisions, and negotiation history.

Minimalist Arceus standards slide compares 3–5h turnaround, 8h guarantee, and 0 billable hours.

Minimal presentation slide shows a customer experience quote with redacted attribution and Arceus confidential footer.

Slide titled “A massive market that raises its prices every year.” presents legal services market metrics and sources.

Infographic compares revenue of major law firms, highlighting Kirkland & Ellis at $10.6B and related market peers.

Slide table titled “Capital is moving to AI-native law firms.” compares funding rounds and valuation signals.

Dark presentation slide outlines Arceus thesis about building a better law firm with legal AI.

Presentation slide contrasts a traditional firm pyramid with an Arceus layered system for legal work.

Presentation slide states commercial contracts are the wedge, with market figures for commercial, employment, and legal services.

Team slide for Arceus featuring Mac Liu and Eugenia Bergantz with portraits, roles, and career bullet points.

Presentation slide titled "The Raise" outlines funding uses for attorneys, engineers, AI researchers, and new practice areas.

Infographic table outlines company segments, average ACV, company counts, and revenue toward a $1B law firm.

Dark promotional graphic for Arceus shows windswept trees behind a statement about next-generation law firms.

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