Back in 1e I used to occasionally encounter players who "killed all the gods" with their awesome characters.
Okay, it wasn't "occasionally", it was every week at the local game club. We had a munchkin infestation.
I ran the occasional game for them, where I made them play by the rules (the horror). One rule I loved pointing out to them (though I never had to actually use it) was in the early pages of the Deities & Demigods where it said something to the effect of, "The DM should adjust the power of the gods as needed to keep them above mortal characters".
Like I said though, I never had to actually change the deity powers, just play them as if they had more than two brain cells working.