I liked Sir Corazin when I first saw him, but I don't think he's a good fit for Forcemaster. It is so easy to cripple the Doublestrike ability with Aegis, Agony, Weak tokens, and simple Armor stacking. I'd prefer to use a creature that helps to shore up the Forcemaster's inherent weaknesses rather than making her suffer even worse from them. Such as the Corrode from Devouring Jelly helping against armor stacking opponents. It is also immune to Weak tokens, immune to Sleep, and can not be Restrained currently. Thus, you cut down the effectiveness of two of the traditional counters to a Forcemaster's damage by using a creature that is very hard to crowd control and fairly long lived (with Resilient and Reconstruct).