best mage build:
for pve:
#shield (without knock back)
#lightning
#firebolt (max or without "cause miss attacks")
#time shift
#heal (without mana regen for easy maps)
passives: max str,int,dex, crit.

for pvp:
#shield(without knockback)
#lightning
#firebolt
#curse

against tank: nekro first, charge firebolt, slightly charged lightning, charged shield,heal (right after he axethrow or almost drained hp), lightning, charged fireball (cuz his jug and nekro aa might be off by now) .... kill.

against rogue: charged shield, slightly charged lightning, charged curse(if he tap pierce not charged pierce), slightly charged firebolt.. if your curse is lucky enough u have chance to win or its **** against rogue after 2 sec