Undead Unluck episode 22 might as well be dubbed "Andy's Past: Victor edition," because that's the bulk of the episode. As Fuuko arrived at Andy's oldest memory, in Washington D.C. on April 15, 1865, she was intercepted by Victor as she barely began catching flashes of memories.
Victor wasn't going to let Fuuko do as she pleased in his head. Victor's reasoning, par for the course for his terse and aggressive self, is that he's the original personality and therefore deserves his freedom. The only way to do that, so he reasons, is to kill Fuuko, take control, and kill Juiz when he's in control as revenge for her sealing him away inside Andy.
Undead Unluck episode 22 thusly answers a ton of questions about Victor, while also showing how Andy and Fuuko have evolved since their original meeting way back in episode 1.
Undead Unluck episode 22 sees Andy and Fuuko fight Victor
Victor's past and reason to fight
While Undead Unluck episode 22 doesn't give Victor's entire story, it gives enough for the audience to have a picture as to how he ended up the way he did. Juiz and Victor started the Union and had a good few successes on the road to defeat God and stopping Ragnarök, but something snapped in Victor as the failures compounded and embittered him.
Following up on Billy's statement in episode 16 about having tens of thousands of tries, Fuuko's visions in episode 17, and the worldwide time-loop revelation in episode 18, Victor revealed that he grew very cynical after he lost count of the number of times they tried to kill God. From the scattered pieces, a picture emerges: Juiz sealed Victor and created Andy.
Now, Victor has his quest: take control of Andy via Fuuko's death and then kill Juiz. He starts this by stating to Fuuko that he's going to kill her as many times as it takes to shred her soul apart since she doesn't belong in the book.
Since he's faster than her, and functionally immortal to boot, he succeeds in killing her up to Andy and Fuuko's first meeting on August 1, 2020.
Andy and Fuuko vs. Victor
Undead Unluck's new OP features a fight between Andy and Victor, with Fuuko lending some Unluck assistance. This was foreshadowing for the fight that happens in Undead Unluck episode 22. Andy and Fuuko end up having to fight the older, more lethal, but less creative Victor for control of Andy's body.
The fight at first seems one-sided, with Victor having more area of attack options than Andy does. This changes once it becomes clear that, due to Fuuko's influence and her speech about death and understanding of life in episode 21, Andy's head is clearer and he's able to fight more creatively.
This includes making blood blades out of his arms, turning his legs into tire treads, and an entire Dragon Ball-style beam struggle with huge blood waves colliding.
What ultimately decides the fight and gets Victor to concede is a good deal of trickery and creativity on Andy and Fuuko's part using Fuuko's Unluck and Andy's finger bullets.
Each bullet hits Victor one at a time, with the Unluck getting progressively worse for Victor: from a simple gas main explosion to stagger him, to a train slamming into him, and finally a plane crashing on him and his head sealed inside the Union capture device Andy's head was supposed to be sealed in.
Victor's respect and further answers
Rather than go another round with the improved Andy and Fuuko, Victor instead offers them his respect and words of encouragement. He also answers a few questions Fuuko has, including about his and Juiz's relationship. Undead Unluck episode 22 reveals Victor respects Andy and Fuuko's progress as a first reveal.
The second is a reveal of his and Juiz's relationship and why they were so close. Juiz herself did imply in episode 18 that they were more than friends, and Victor confirms it: they were a couple. The reason why he wanted to kill her was because he didn't want her growing cynical or dying frivolously since she wasn't immortal.
He also says that the memory isn't important since Andy and Fuuko are better off now. As long as they keep moving forward, keep being creative, and keep their heads high, they both can beat God especially if Fuuko's Unluck keeps progressing. Victor even said Fuuko and Andy reminded him of him and Juiz.
Final thoughts
Undead Unluck episode 22 closes out with Andy and Fuuko separating again, ending off with Fuuko leaving the book. Andy is extremely thankful for Fuuko's help, as the new experiences and memories will help him in battling the UMA Autumn and avoid Anno-Un's prophecy of death from episode 20.
The two episodes may not have answered everything about either Andy or Victor, but they gave the audience enough for now to serve the story being told. Andy and Fuuko are now enough to handle Autumn and possibly Under should it come to that.
Undead Unluck episode 22 also serves to humanize Victor, he's not just Andy's original persona and wild, battle-crazed self. Victor wants Juiz to forget about him, be reborn, and live a normal life free of suffering and the misery that they went through. Juiz, ironically, wants Victor to smile again.
This won't be the last audiences see of Victor. Undead Unluck episode 22 revealed his hidden depths and ultimately helped to make his character more than just the cold, fight-obsessed demon he was originally thought to be.