I decided to try using the owlbear with elixir of colossus to stomp the githyanki patrol from the top of the bridge. Damage and effectiveness could have been boosted further by casting enlarge on the owlbear (which I didn't do in this particular fight) and possibly clumping all the enemies together with a preemptive void bulb. I'll probably try that on my next playthrough. On a side note, I did attempt to owlbear jump onto the ancient red dragon before it flew off, but for whatever reason, it did exactly 0 damage when I tried. I'm guessing this ancient red dragon wasn't meant to be killed at this point in the game at least.