UFO Ver.2

Why aren't there more builds/uses for this?

I understand that it's active is really bad unless you're just starting the game, but couldn't the leader skill be really good for certain dungeons if you don't have something good?

I already have a Kirin, so I don't necessarily need him. But his leader skill is more reliable than hers if you have something that reduces your health to 1. And pretty much every single dungeon you use Kirin in is less about taking any hits from the boss and just more about using Echidna and nuking it down it 2 or 3 turns.

Don't get me wrong, Kirin is definitely better. UFO V2 doesn't have a gravity, or good stats to clear fodder floors. And yeah, if you had something that would reduce your health to below 10%, which would more than likely be something like Lucifer or Lu Bu, it'd probably just be less work to use them. But there has to be some use for this guy, right? 5x damage is nothing to look past, regardless of the requisites.

If you were to get under 10% on a fodder floor or something, you'd have unconditional 25x damage to sweep everything else. AND it's for any dropped orbs you can get your hands on; it's not discriminant to any monster and doesn't stifle your combos by making you focus on getting specific elements matched rather than getting a good combo.

A physical team with a max skilled King Bubblie could easily destroy almost anything. The tendency for physical monsters to have high health and low recovery means that 10% health would still be a hefty chunk even when low, and once you got where you wanted you wouldn't have to worry about avoiding recovery orbs to stay under 10%. But even then, you could easily use someone like Siegfried or Gigas to get rid of the hearts.

I'm sure there are more uses for him than listed. Is this just a case of not being versatile enough and/or worth investing the exp into? :p

Good for getting Nebradisk

I have a use for this guy - Wednesday Masks on Legendary.

My team:
Max level and awoken Ama-O, RCV > 834
2-element gravity (DQ Hera)
2-element gravity (D/L Hades)
2-element poison (Can use D/D Lilith, but I am lucky to have Phantom Odin)
UFO V2
Max awoken GOdin

Follow the floor directions on Wednesday Masks Legend posted in comments. When you get to the bosses, target and poison the blue mask, and wait til he is dead. Then you'll have 1 turn to deal with the green mask. UFO's active should take care of that. Easy-peasy, and you don't have to worry about prematurely killing the green mask before the blue mask is dead.