What to do with Raven? Quick question

Brave Axe isn't really optimal on most units these days, just +atk Cherche, arguably Frederick, and I think quad WLissa. My recommendation? Wait until you pull a 4* Raven with either +spd or +atk, promote that one, and merge this one into that. Ideal would be +spd/-res. You could also learn Basilikos on this one, then merge down into a 4*+10 merge, but I usually recommend merging at 5* for potential 5* pity breakers in the long run. Raven is absolutely insane with minimal investment, so I highly recommend it.

If you're planning on building a Raven, then keep him. You can always go back to him later with a Raven with better IVs, 5* him, and then merge the +Res Raven into the better IV one.

And it's not like the bane touches his most important stats, Attack or speed, and he's gonna become an extremely glassy canon thanks to Life and Death 6, so really there's no need to look at boons and banes for him except for speed. His attack reaches incredible heights, and his speed is already really good.

Raven might be the one character that people don't "need" boons and banes for (again, not including speed, but even that's debatable).

depends on how many feathers you have. If feathers arent an issue just give away his brave axe you can easily get a high merge raven over time since. Also right now ur not using him but giving a unit brave axe+ will be a noticeable difference while +1 merge isn't going to be a huge difference.