The forcemaster has the potential to be one of the best tanking mages in the game, but I'm having trouble figuring out why she'd ever want to tank instead of rushing. Force crush does damage over time, but I don't see why the forcemaster would want to use it, since it's so expensive for her to use if she's rushing. It seems to be a waste to not rush when you have access to Galvitar, since it's spinning slash attack always either has sweeping to get past guards or double strike to deal 8 dice on the enemy mage.
But she has access to a lot of other spells that feel like they'd be really useful tanking. Forcefield, force orb, force sword, dancing scimitar, force crush, position control via spells like force push, force wave and repulse, and she's great with zone attacks because she usually has few to no creatures. She could do a lot of things to make her opponents' choices less useful or useless, such as block, reverse attack, steal equipment, fumble, suppression orb, wall of force (in front of a spawnpoint or something), stumble, force hold, charm, mind control, etc. a lot of the out of school choices she already uses could also lend themselves well to a tank strategy: mongoose agility, cheetah speed, hand of bim-shalla, armor, regen, etc. She even has a built in defense that would be really great with temple of the dawnbreaker!
There's just one problem. Forcemaster is usually so much better rushing (with or without a buddy) because of Galvitar. As far as I can recall, I have only seen two possibly viable forcemasters that could take sufficient advantage of Galvitar without rushing: a swarm build murphy made a while back that was similar to falcon swarm but might have been rather weak to aggression (though it's been a long time since I've played against it) using max spores and psyloks, and a forcemaster I made that turtles against rushes and rushes against turtles.
I'm thinking in order for a forcemaster tank to be worth it, you would need some sort of alternative to Galvitar. Maybe something that has a ranged attack, so she could kite. A forcebow or something like that.
What do you think?