let the master of ideas come in XD (jk)
[Damage Over Time] - spell will deal damage over time. (poison, shadow strike)
[Synergy] - spells that "compliment" the other. (Drunken haze and Breath of fire, banish and anything else)
[Blood] - Bloody Theme
[Global/(any other theme)] - spell is global
[that Ying&Yang nonsense] - Poot's idea..
[Blockade] - the spell will create some kind of blockade that will stop a unit in its tracks, or serve as an annoying obstacle.
[Domino Effect] - Boom goes to Boom goes to Boom etc.
[Friendlies] - Friendlies comes out to aid your hero (Stamepede, summons, locust swarm, raise dead)
[Player Controlled Ability] - this is confusing but, a spell, that will be activated by a player. (Spamming, Slows all units on the players screen, clicking on an enemy unit to damage it, etc.)