I have a few ideas for the possible improvement of Ultima Enhancer:
1) When it is cast on a player, it buffs every group member of the same class. A bit like the Greater Blessings in World of Warcraft. In other words, cast it on an Archer and all Archers in the group will receive the buff.
This change would make the most difference when you have a full group of 11 players.
Coding this might be a pain as I don't know of any spell mechanics in Mir which work this way.
2) Add the static shot mechanic to the spell.
3) Incorporate the Poison Cloud mechanic. The tao lays down a 3x3 patch on the ground, which provides the buff to allies which walk over it.
4) Make the spell a 3x3 or 5x5 area spell. (In my opinion the worst improvement which could be made to it :welcoming
Edit:
I've had Idea 1 for a while now, the others popped into my head writing this post.
Idea 3 is my favorite!