This is a collab event currently going on for the next 30-ish days in Honkai Impact 3. Asuka is playable and can be unlocked for a limited time. There's also a bunch of stages based off of Evangelion, but using Honkai characters in place of the Eva ones, with the added bonus of Asuka actually being there.
This is a self contained story, so you don't need to know anything about Honkai going in. All it uses from the Honkai story are characters and terms. Honkai is a little clunky by nature of being a mobile game first and foremost, but the majority of their effort goes into the gameplay so it's pretty fun to play. Their translation could use some work, but it's serviceable and gets the information you need across.
Asuka is my favorite character, period. And action games are my favorite genre, so getting to play as her in one is a sort of dream come true for me.