I feel like Kane would have energy draining powers. Like, you can't harm him with electricity, lasers, or intense heat because he'd just absorb all the energy. Granted you could overload him but he could take it in a bit. He'd also be less efficient at absorbing kinetic energy, meaning punches can still harm him, especially if you catch him off guard.
He can't release the energy he's absorbed, but it does strengthen and energize him, making him a bit stronger and faster and think clearer overall. You can tell he's super energized because his hair flares up and his eyes glow silver.
Most of the time, all he uses this power for is to replace his need to eat and sleep, so he can play video games all night. While drawing energy from power outlets raises his electricity bill significantly, even with him still buying snacks, its ultimately much cheaper than groceries.
((for next poster: please try and come up with something besides shapeshifting / stretching; she already has those powers!))