I always thought it was such a waste that Kaidan was never shown using his awesome biotic powers in any cutscenes. I mean, the dude is an L2, his biotic power is at LEAST Asari-level, if not higher... but all he ever uses (outside of gameplay) is a pistol or a rifle
I imagined this scenario in my head: Shepard is down after being hit with Harbinger's beam, the Reapers are swarming around them, and Kaidan is out of ammo. No choice left… time to max out his L2, no matter the cost. As he takes down wave after wave of enemies, his power is taxed to the limit, and in a final all-or-nothing shot, he supercharges his barrier to explode and destroy the remainder. Then, his mind shattered from L2 exertion, he collapses by Shepard's body... deathly still.
It would be tragic, but sacrificing himself to save Shepard is totally what he would do. ( ;u; ) I'm very tempted to flesh out this story properly as a short comic, but it would take forever @__@