Debateable.
Lv15 mage doesn't nuke AT ALL.
Lv15 mage doesn't tank AT ALL.
Unless your using founders. But at 15 founders makes everything OP.

I challenge any 15 mage to tank a bear (talon,fb,xbow,sbl) if you're stood next to a 2/3 slash bear who knows how to play. You'll die.
Lv15 mages are soully based on kiting and/or mana saving then "Nuking".
This is why most noob 15 mages aren't very good because they don't know how to kite vs a 15 bear properly.

Lv15 mages are mistakenly shown as tanks as the lightning debuffs stacks and makes a huge difference to dmg.

I would love to see your 15 mage ig, please teach me this so-called "tank" & "nuke" you speak of