You can buy indulgences from coaligned priests, which will remove or reduce god anger or negative alignment.

You can wish for your god to be mollified, which has the same effect as doing it at an altar. Not specified if this should break atheist conduct, but it probably should, since you’re affirming there is a god that you want to placate.

The parser could look for “forgiveness” as the phrase to trigger this.

Intelligent artifact weapons reduce their damage (perhaps nullifying any bonus damage given by the artifact, or dealing half damage) if you are crossaligned, have negative alignment record, or your god is angry at you.

Converting an altar is made easier to do in terms of RNG (either increasing the odds or making the conversion guaranteed after some number of sacrifices), but in compensation for that, all attempted sacrifices cause the altar’s god to get angry at you and smite you, with the penalty dependent on your XL or level difficulty. They can do things like curse your items, give you negative protection, send minions to defend the altar, and blast you with lightning and disintegration if at a high enough level.

Sometimes when your god is angry at you, they will grant a gift when you sacrifice to them. But the gift is a negative item, because the god is trying to kill or mess with you.

When removing a helm of opposite alignment, after restoring your original alignment, increment your god’s anger. Do it after removing the helm because then your original god gets angry at you for putting the helm on, not your new god.

If god anger is tracked separately for each god, it doesn’t need to be done this way; merely make your original god angry when you first put on the helm.

If you enter the temple of a god who is angry at you, all monsters on the level become awakened and aggravated. This should print a more menacing message than the standard “forbidding feeling” one. (Note that a proper implementation of this requires that gods’ anger levels be tracked separately for each god.)

Define gods as having an associated holy animal (e.g. crocodiles are Offler’s). If you sacrifice that type of animal to that god, it immediately angers that god.

Make it easier to destroy non-high altars, perhaps by something as simple as digging them, but destroying an altar will cause its god to smite you hard. If you destroy a crossaligned altar, your god rewards you for it.

When you escape the dungeon by leaving on the level 1 stairs without the Amulet, your god is immediately set to be angry at you (for abandoning their mission). This will have no effect on the game since it’s ending, but end-of-game enlightenment will show that they were angry with you. Possibly disable this if the hero had the Amulet at some point or is carrying an unidentified fake one.

Confused cursed scroll of punishment decreases god anger by 1.

Vomiting on an altar should offend its god, as should digging on it.

Cannibalism angers your god instead of removing telepathy.

Change the confused effects of the scroll of punishment: blessed mollifies your god if angry, uncursed increases anger by 1, cursed increases anger by 1 and your god smites you.