The Icehands have a straightforward but deadly technnique. They will rush towards their target, invoke Deep Freeze to prevent them from running away, then punish the severely slowed down target with Lightning Touch. Against warriors and rangers they'll use Blurred Vision and against spellcasters they'll use Maelstrom.
They tend to go for spellcasters no matter how well the party uses its tanks. It is important while warriors tank them that other party members strike them from afar without letting them into the aggro cricle.