There are currently 2 op spells that have no cool down, Comet Fall and Push Up are the two spells that need to have cool down affects added onto them because sorcerers spam outside depot and i walk out i have 4.7k HP and i get 1 hit, that is lame.
Not to mention that its been proven by tones of people that equipment that protects against damage has NO AFFECT. So don't waste your money just yet on items because none of them work unless they do damage.
Another thing is that necromancers can summon a beast called Inner Darkness which has high protection to damage, tons of hp but dies slowly over time, takes up 95% of their mana and drains the targets mana like hell, and does insane damage + their want that does 550 damage a tick. On top of this they can drain their targets mana, now that blows.