Earlier in the first act, John Laurens challenges Charles Lee to a duel after he disparages George Washington, and Alexander Hamilton and Aaron Burr act as their seconds.
The party goes to Vasselheim to find allies, and Grog discovers the Trial Forge, a temple to Kord, the Stormlord, led by Earthbreaker Groon. He seeks training from Groon, and Groon challenges him to prove himself in a fight. During the fight, Groon recognizes the evil in the sentient greatsword Craven Edge wielded by Grog.
Vax and Scanlan are picked to help as requested by Groon, but Groon remains defensive and protects himself with the Sanctuary spell effect of Tranquility. He then uses a high level Monk ability called Quivering Palm on Vax, but the Dungeon Master Matt Mercer ruled that he held back from its full power so it only did 10d10 damage instead of reducing Vax to zero hit points.