On just theme, other than the Scorpion Shield from Mace you mentioned, I would give Power another look.
Power Build Up is an awesome power for anyone, but especially ice/ice corrupter. It's a combination of Build Up, so more +damage and +tohit, AND Power Boost, which boosts all mezzes, tohit, slows, defense, and other stuff. You have two holds in ice blast and just about everything adds slow to your opponents. Unfortunately, it doesn't boost your ally shields as they also have resistance and that ends up negating the boost. But it would boost maneuvers, combat jump, weave, etc. https://cod.uberguy.net/html/power.html?power=epic.power_mastery.power_build_up&at=corruptor
Temp Invulnerability is a fairly basic smash/lethal armor. But you can add the two unique IOs to add another 6% defense as well. Force of Nature is essentially Unstoppable from Invulnerability so it has the big crash at the end. Some people hate that, others don't mind.
Alternatively, the only "ice" powers would be in Leviathan - Hibernate and Shark Skin. While Shark Skin doesn't sound particularly icy or glassy. it provides smash/lethal/cold resistance and can be used with minimal effects to just be a slight aura.