Kills count, disguises match, bullets point forward
This is Apoli 1.109.1 and Origins 1.47.1: four fixes, all on Fabric 1.20.1, Fabric 1.21.1 and NeoForge 1.21.1. Nothing in your data packs needs to change.
apoli:action_on_kill fires for every kill
apoli:action_on_kill only fired when the entity you killed had a power of its own. Most mobs don't, so the example on its page, healing when you kill a skeleton, did nothing in a plain world. It fires for every kill now, whatever you killed, and that includes powers written under the legacy self_action_on_kill ID.
Disguised players take the target's arms
A player disguised as another player with apoli:disguise_as or /disguise player already wore the target's skin, but kept their own arm model. A player with wide arms disguised as someone with a slim skin was drawn with wide arms, so the skin didn't line up. The disguise now uses the target's slim or wide model too, in third person, on your own first person hand and in the inventory preview, and it works in both directions.
Custom projectile models face where they fly
A projectile wearing a geometry model from apoli:custom_model_render only faced the right way when fired north or south. Fired east or west, it flew backwards, pointing at whoever shot it, and fired diagonally, it flew sideways. Projectiles now face their direction of travel in every direction, with or without Flywheel.
The side of the model that leads is the one Blockbench labels north. If you turned a model around to make up for the old behaviour, turn it back.
model_color alpha in first person
The alpha of apoli:model_color now shows on your own first person arm, and matches the rest of your body in third person: an arm at 0.5 is half see-through, without the inside of the arm showing through it.