I have a Water/Invul, Fire/Invul, and a DP/Invul Sentinels and I like them all. IF I had to pick a favorite Blast Power it would be my Water/Invul and my least favorite is my DP/Invul. On the other hand my DP/Invul is my toughest since I turned him into a meat shield. He has Provoke, Melee Radial Incarnate, Intimidate (Fear), Unrelenting (Heal), and Barrier Incarnate. He survives longer than the other two.