Help with a custom state (YEP_BuffsStatesCore)

[LLewliet]

Hello! I would need some help with a custom state I'm making with Yanfly's Buffs & States Core. To sum it up, I'm trying to create a state that makes my actor gain a 0.5% buff in atk and m.atk and lose as much in def and m.def everytime he is healed (no limits, and it'd be appreciable if he doesn't get the buff when he's full life). I tried several things but only ended up with syntax errors, especially because I struggle finding how the buff parts should be written. I hope someone can, if not write everything, lead me to how properly do it.

PS: Since the class has a skill that inflicts a "leech seed" state on an enemy, the state should also allow sef-healing.