YouTD

Providing trigger chance and attack damage scaling off spell damage is a unique effect, I'm not sure I understand the role the tower is intended to play. The spell amplification effect is fairly weak and inconsistent compared to other, similar towers (Black Dragon Roost, Skeleton Wizard both around 30% damage amplification not limited to spells), and doesn't cooperate with the idea of giving additional attack damage to a spell tower.
I think the buff is a very cool way to make a spell carry turn into a hybrid carry. A more standout version of Volatile Inscription could really make this tower pop. I don't like criticizing without providing ideas, so here are the only ones I thought of;
-The buff stacks
-In addition to amplifying spells, it reduces armour (to support the hybrid style)
-Instead of amplifying spells, it works like a reverse Vol'Jin malediction where it turns spell damage dealt into [magic] damage when the buff expires
-It's a skink style buff that has towers around it applying the effect instead