Mages can solo anything on timeless isle. If you get any of the altar buffs (25% haste+crit) combined with some of the item on-use effects like increased stats and 60k dmg/heals literally anything dies in sub 30 secs, even the 23million mobs.
If you're soloing, going invis will almost certainly reset the fight.
Which is why I said Cold Snap is better, for soloing content.
Originally Posted by Polarthief
For soloing content. GI is significantly better and only half the cooldown if you're allowed to invis.
"For soloing content." was referring to Cold Snap because that's what I quoted. Cold Snap is typically useless outside of PvP and soloing as GI and Cauterize will surpass it on almost every other scenario due to lower cooldowns and more powerful survivability.