Relationship between Percy and Vax'ildan

Before the Storm
Percy and Vax were once very trusting of each other, the two of them having a friendly and humorous rapport. At one point during the group's escape from the Underdark, Vax even grabbed Percy and kissed him on the cheek.

When Percy shared his backstory of his home being overthrown by the Briarwoods, Vax was among the first to offer his support in getting Percy's home back. Throughout the group's infiltration of Whitestone, Vax attempted to be a voice of reason to Percy's increasingly cruel behavior while still supporting his friend. When Vox Machina discovered Percy's youngest sister Cassandra was still alive and went into the castle to find her, Vax was the one to stumble upon Professor Anders using the young woman as bait to draw out the group. Vax rushed in to attempt to save her and, following the scuffle, Percy gathered up Vex'ahlia's scattered arrows and whacked Vax with them, chastising him for being so reckless. Vax later told Percy that while what he did was reckless, he did it to save Percy's sister and he hoped that if Vex was in danger Percy would rush in to save her too. Percy immediately agreed. Down in the tunnels beneath Whitestone, Vax was possessed briefly during combat along with a few others. Percy attempted to shoot Vax but misfired, the gunslinger nonetheless feeling relief that he didn't shoot his friend.

Following Whitestone's liberation, Vax kept to himself during the group's break before Winter's Crest, avoiding everyone including his sister with the one exception being Percy.

Before heading down into the Raven Queen's tomb in search of a Vestige to help them fight the Chroma Conclave, Vax and Percy reflected on where they were as people. Vax told Percy that he'd always have a family in Vox Machina and Percy confessed that he was starting to imagine a better version of himself. Percy then encouraged Vax to pursue happiness, implying that he was going to try to as well. This conversation would be one of the last amiable interactions the two would have for quite some time, as the events that unfolded in the tomb would leave a lasting impact on their relationship.

A Broken Friendship
Things went downhill fast for Percy and Vax's friendship after Vex'ahlia's death in the Raven Queen's tomb, caused largely by Percy's own negligence, and remained that way for a long time. Vax blamed Percy for his sister's death and Percy agreed, with Percy approaching Vax after the ordeal to apologize. Vax then apologized to Percy before punching him in the face, a blow that Percy stood there and took. The two then curtly parted ways.

Vax remained distrustful of Percy, continuously questioning Percy's actions and morals throughout their journey. This divide between them only widened after the revelation that Percy was the one to give Craven Edge to Grog while knowing of the sword's sentience came to light following the goliath's soul being sucked into the sword.

Percy reached out to Vax with what could be considered an olive branch multiple times throughout their feud, with Vax either ignoring or outright refusing most, if not all, of them. At one point Percy even made him a raven skull brooch filled with sweet-smelling herbs using a cast of the raven skull Keyleth gave him and the jewels he won from Vox Machina's cannonball contest, the intent being to help with the stench of death and feathers from Deathwalker's Ward. He even encouraged Vax to pursue Keyleth, much to the rogue's confusion.

Unbeknownst to Vax, Percy visited the Raven Queen and took blood from the pool in her temple. Percy brought Vex along with him while he set up a small shrine to the goddess in Whitestone and entrusted the care of it to Zahra. When Vex asked who the shrine was for, Percy or Vax, he told her that it was for Vax so he could help them. When Vex returned to the castle Vax cornered her and told her that "he's charming, but both eyes open", referring to Vex and Percy's flirtations. Vex denied knowing what he was talking about but Vax wasn't fooled.

Vax's distrust of Percy's intentions with his sister followed them on Vox Machina's trip to the Feywild, where Percy titled Vex to get back at the twins' father and boost her self-confidence. Vax got Vex by herself shortly after and told her that he wasn't fond of what Percy did, explaining that he thought it was "like gilding a lily".

Mending What Was Broken
When the group returned from the Feywild, Percy finally showed Vax the shrine to the Raven Queen he'd made for him and the two had a frank discussion about their relationship. Percy told Vax that he wants to be in the rogue's good graces again, but for the time being requests that he "never trust him". Vax agreed, informing Percy that he still continued to see him as a friend despite their strained relationship. The two have since continued to repair their relationship, with Vax even going so far as to tell Percy that he considers him like a brother.

Following Percy's death at the hands of Anna Ripley, Vax was visibly distraught at his friend's death. Vax assisted in Keyleth's offering during Percy's resurrection ritual, and upon success of the ritual Vax immediately helped revive Percy from unconsciousness. Vax was the one who encouraged Percy to return to his room and sleep it off. After Vex shared the letter she found in Percy's jacket, revealed to be a will of sorts, with the rest of the group, Vax read the letter aloud. The part of Percy's letter addressing Vax said that Percy sees a lot of similarities between the two of them, which he knows is a bad thing. He continued on to tell Vax to pull himself together because someday Vex and Keyleth may need him.

While Vax's relationship with Percy improved greatly, he still remained wary of Percy's relationship with Vex. However, he nonetheless encouraged Vex to confess to Percy, although he encouraged her to keep her eye on him. Vax's opinion of their relationship increased significantly following the two becoming a couple, with Vax at one point even encouraging Vex to stay in Whitestone with Percy and "explore activities" there.

When Percy showed interest in Vax's plan to deliver the journal of Opash to the Raven Queen's temple, Vax asked Percy if he wished to accompany him and Percy agreed. During the trip, the two of them briefly discussed how glad they were that their relationship is better than it was previously. Vax told Percy that he likes the version of him that his relationship with Vex brings out and Percy agreed before he then told Vax that he likes the version of the rogue that isn't afraid, prompting them to hurry up with delivering the journal so they can get a drink and get Vax feeling better. On their way back, Percy told Vax that it was his job to find happiness before he's pulled away on his duties to the Raven Queen and that Keyleth deserved better than Vax at his worst. Percy then proceeded to slap Vax on his rear before walking off to join Vex and Keyleth at the bar.