What do you find as the most useless and most useful staff hex?

[Edward Edgemenace]

Blast: Cute. Good way to aggro something VERY quickly.
Soul flay: Good for leveling up until you have wither.
Pestilence: Good if you like the color green.
Wither: My favorite...fast charging, strong and hits in all directions.
Flaming skull: Longer range than blast, but prohibitive charging time.
Banish: Obscene charge up time. Mostly useless.
Desolation: Fatal charge up time. Entirely useless.

Concentration: Not bad, but unlocks AFTER you needed it.
Spirit lore: Mega-fantastic. This makes the big difference.
Conservation: Unlocks long after you don't need it anymore.
Spirit mastery: Pretty good. Not as good as spirit lore, but still really good.