I thought you were a good transmuter, should have been a great addition to the Fortress. Goodness knows what a trans/war pair can do. As for invokers, did you take 'Battlemage Training'? It is very good alongside quickening, defensive spin staff, and slowing your enemy. Outmeleeing warriors is not unheard of. Axe warriors, anything, once you get the slow. 'Paralytic Opportunist' is another good one.

Good luck with the next...