So there are now only four attack types that still aren't actually on any weapons or used in combat at all. It would be fantastic if the full spectrum of attack types was finally completed, and GK is honestly not too far off from that right now.
I figure I'll toss out a few ideas for them, and other people are welcome to join in. :]
Acid - Corrodes your opponent's AC or WC, reducing it temporarily.
Drain - Drains your opponent's spell points.
Paralyze - Stuns your opponents for a short duration.
Deplete - Absorbs food points from your opponent. (Or possibly grace, although the icon is currently showing a piece of food.
)