I have a WB/Invul/Leviathan at lvl 50 and they are great and lots of fun. The Invul is a great Armor set for Sentinels. It doesn't need enemies nearby to increase Defense like Tankers or Scrappers, so the defense is slightly higher amd this allows your to reach defense Soft cap easier. The Damage is a AoE beast; however, the damage is not the strongest. With that said you have to be creative and use procs wisely and it can help the toon a lot. The Epic Powers is where I got Knockout Blow and it's my boss killing attack. With the -Defense from WB and -Resist Proc in some powers, Knockout Blow hit hard. I ended up Slotting KO Blow with 2 Hami Acc/Dam Enhancements and 4 Damage Procs. I know its not the best slotting, but it works for me. I hope this helps a little.