Kid Omega is a staple-level ally with great utility regardless of deck composition. He meets acceptable efficiency if all he does is activate once and block, but the Response ability adds a really nice flexibility. It's a place to put an extra resource that might have gone to waste the turn you play him, and if there are multiple enemies or schemes out it is simply a strong, efficient ability. Kid Omega is an X-Men, which means he can be used in the "To Me, My X-Men!" archetype, which rewards allies with good enters-play abilities. He also fits into Uncanny X-Men decks, where he won't clog up your ally slots for too long given his low (yet efficiently-used) hp. He has Psionic synergies as well for a Power of the Mind / Psimitar strategy. A good baseline with high upside in certain decks or situations...an amazing card!