In the main games, Shell Bell holders recover 1/8th of the damage they inflict to an opponent.

In Pixelmon, it seems that a shell bell user that switches in gains HP at the beginning of the turn (rather than at the end, after they deal damage). This is important in settings where Entry Hazards are up, and a FEAR mon is switched in (FEAR mons are typically level 1 pokemon having focus sash or sturdy).

TLDR: Shell Bell isn't supposed to be recovering HP at the beginning of a turn/recovering HP when no damage is dealt, but it does do so in this Pixelmon mod. The Shell Bell also shouldn't be recovering if the mon is switching in at the beginning of the turn (Ex: Poke 1 faints, Poke 2 with shell bell is brought in next turn) Poke 2 shouldn't recover HP.

Haven't tested it yet, but this bug might extend to Leftovers and Black Sludge as they are also HP-Recovering held items. They shouldn't be recovering anything if the pokemon is switching in at the beginning of a turn (it SHOULD work if it is the end of the turn though)

Hello! I haven't been able to reproduce this. In both single and multiplayer, wild and NPC battles. Could you tell me exactly how you triggered this?

This is most apparent in PvP battles. Here is how the glitch triggers for me:

Turn 1:
Player 1 has a pokemon that can set up either Stealth Rocks or Spikes
Player 2 sends out a random pokemon (doesn't matter what this pokemon is)

Turn 2:
Player 1 sets up Spikes/Stealth Rock
Player 2 uses tackle with the random pokemon

Turn 3:
Player 1 selects an attacking move
Player 2 sends out a Sturdy level 1 Aron holding a Shell Bell
** Level 1 Aron switches in, and takes hazard damage**
** Level 1 Aron's Shell Bell recovers the HP it loses**
**Player 1's attacking move hits and brings the Aron down to 1 HP, but because of the shell bell activating, instead of killing, the Aron survives on 1 HP because its sturdy ability activates (which it wouldn't of had if the shell bell didn't recover Aron's HP**

Thank you for the clarification! Seems to be an issue with entry hazards as a whole. Thank you for the report!