I just had the unfortunate experience of crafting a graviton charge with a medium damage bonus against undeads, and I have a couple of questions:
1. Will this UV reduce the chances of this particular bomb getting more UVs when it gets upgraded further?
2. Is there any way this damage bonus can increase until it becomes vaguely useful?
3. Any other advice as to what I can do? I actually intended to sell it, but now I'm not too sure.
UV damage bonus clashes with damage type
When you upgrade it you have the choice of keeping that UV with no chance of a different one, or removing it and having the normal chance of getting a new UV.
Just to clarify some things :
1. if you already have an uv, there is 0% chance it changes if you don't drop it. If you drop it, the chances to have another uv are the same than if it had no uv.
2. no. It's a shadow bomb so Undead UV is useless. And anyway, as Bopp said, Vortex bomb are not used for damage. I would try a new UV, you never know, you could have a CTR uv, or at least a useful damage UV (slimes or gremlins)
3. it's supposed to be really great at 5* (that's what i heard, mine is still 4*, and good enough when i use it, which is not often). Keep it if you plan to use it. Anyway, just know that it's not worth unbinding it : i doubt anyone would take it with additional unbinding costs.
Well, Graviton Vortex isn't about damage. If you use it "correctly" (i.e., break the vortex with a big charge attack), then the only damage it does is a tiny, tiny initial explosion.
When you upgrade an item, you can choose whether to preserve the UVs on it, or go for new UVs. In this case, I would certainly go for new UVs. On this bomb, you want CTR and not really anything else.
(Disclaimer: I don't have this bomb.)