I love my Energy/Invul. He has defence caps to all damage types but Psi, S/L resist cap, perma-hasten, perma-HP Cap (if I want it through dull pain), and great ST damage. After accolades he also has 135 endurance, which is great.
AoE is a little light perhaps but that's more of a choice since I skipped the cone attack.
Invul is a hugely underrated power set on Sentinels. I guess its not flashy and, dull pain aside, very passive, but as far as click-and-go survivability goes, it's a beast. Very keen to try pairing it with ice blast for the two rains.