There are two sides to every coin. It is true that Icy Gaze was imprisoned for capturing all Element bearers and almost killing them, chickening out at the last moment. It is also true that he did all that for a sum of money a pegasus of his career almost never has the chance to see and on the orders of princess Luna, possessed by Nightmare at the time.
It is understandable why he might be just a little unhappy about his current home, Canterlot castle dungeon cell, and wants to spread his wings again.

Also, Twilight "I'm not insane, stop asking!" Sparkle attempted to build an artificial intelligence to serve her needs and finally activates it.

I'm sure a pegasus and a bucket of bolts won't end up going against each other.