I'm going to assume he gets to use both of their spell lores. Which gives him the choice of:
- His AoE: 18" AoE, everything suffers 0-D6 mortal wounds depending on a diceroll
- Solar flare: roll a dice for each model in a unit mortal wound on a 6.
- Stone attack: roll dice equal to the casting roll (so minimum of 10 for teclis) if you roll higher than the target's save value deal a mortal wound
- Bury: Roll a dice, instantly kill the target if you roll higher than the wound characteristic, or deal D6 if you roll a 6 and that isn't enough to beat its wounds.
- Living divide: D3 damage on a 2+ to every unit in a line.
- Arcane bolt that's guaranteed to do D3 damage (least exciting spell, but hey it's there
)
And then there's of course all the usual endless spells which would normally be difficult to cast but now always succeed with their varying effects.
He basicly has acces to single target nukes, loads of AoE, anti-armour nukes & anti-horde spells and stands a decent chance of annihilating whatever he goes for if he focusses fire with plenty of targets of oppertunity for some accidental AoE. Hell, stone attack alone with the guaranteed casting rolls allows him to pretty much kill any support hero at will, and severly maim most major heroes. If he wants something dead with his spells he should be more than capable of pulling that off.
As for the endless spells, I don't think you're going to enjoy having 4 of em being thrown at you at the same time, which is something he can do easily & viably.
And we're one of the few armies who might actually be able to provide some resistance with our infinite range unbinds and +1's to unbinds for the slann. Though even then some of those guaranteed 10's are going to make it through (not to mention the guaranteed 12's or just guaranteed cast...). Armies with lesser casters will just have to deal with being barraged by him with no hope of doing anything about it.
And that's of course ignoring the amount of utility spells he has as well (I like that we're slowly getting more utility spells, but they got a lot of em compared to everyone else. And very powerfull ones at that)
His mediocre melee profile and high cost might keep him in check. But dealing with him is probably going to be frustrating for most opponents, even if they do ultimatly win. O and that's of course ignoring the fact that your opponent has other models too... Which is kind of the general issue with these super powerfull ones, they end up being virtual 1 man armies. But since they're not 2000 points they still have plenty of support as well.
