Here's my situation. In an encounter I have coming up next week, an epic aerial battle between an Angel and a powerful necromancer rages overhead a group of low-level PC's. Attempting to assist in that combat would be like a gnat weighing in on nuclear warfare, but as the blood of the necromancer begins to rain down around the players, zombie-like undead start to rise from the ground.
Putting myself in the shoes of the PC, I would be seriously distracted by the almost God-level combat taking place directly overhead.
My initial idea to simulate this was to play a video of the battle taking place overhead during the combat encounter, but that would pull the players away from the game when it isn't their turn (thanks to the commenters and @GrandmasterB for pointing that out).
How can I accomplish this effect in-game without actually doing something to distract the players?