they tossed wave upon wave of asset destruction until the killer android's kill limit was met.

Anyways to the question .

If you have a terrain asset in play, and a killer android, your opponent plays their own terrain, can you respond with killer android when their terrain enters their staging area to destroy their terrain instead of yours getting destroyed.

Good question!

"2.14.2.9 Terrain
Terrain: Only one Terrain card may be in either player’s staging area at any one time. If a Terrain is added to either player’s staging area, all other Terrain cards in all staging areas are destroyed.
2.14.2.9.1 The Terrain keyword is a continuous ability."

Killer Android:

"R Commit: After your opponent plays an ability that destroys an asset, cancel its effects and destroy 1 asset."

Your opponent's Terrain keyword is the ability that is destroying your terrain. But unfortunately that Terrain keyword is a continuous ability, so it's not "played." This means Killer Android cannot respond to the Terrain.

Also: good Futurama reference!