How do I change properties of an armor to avoid debuffs?

I'm creating a modpack in 1.16.4 based on DDSS (1.12.2). I download all the mods available for the version, but I'm having a problem with Avaritia Lite. The armor is very very strong and it's almost impossible your life decrease, but you still receive debuffs (wither effect, poison, instant harm, etc). So I decide create my own mod and make an armor with the same skin, but differente properties. How do I create an armor strong enough to don't receive damage from any mob and don't be affected by negative status?

Another problem is that I don't have the ability of fly. Isn't too important 'cause I have an angel ring, but will be cool have the armor more near of the original Avaritia.

UPDATE:

I test and using the command " /effect clear @p [effect] " I can remove negative effects, but how I check if the player is suffering a debuff?