Ulmaguest?

What's it for?

It takes zero hp on all units I've tested it on so far, anyone who knows?

Ulmaguest works like so:

Caster's max HP - caster's current HP. It hits for the same amount of damage that the caster has received. Much like Beowulf's Shock ability.

Oh....ok thx.

Que es Ulmaguest?

It's Dark Behemoth's Monster Skill. Also, I think Ultima Demons have it in their skillset.

Spiffy.

The correct translation, of course, being Almagest, which is also one of Neo Exdeath's special techniques in FFV.