There are 3 main builds for difficult tera raids:
Iron Hands holding booster energy with moves belly drum, drain punch, wild charge/close combat and protect
The idea is to max your attack witth belly drum and then restore and mantain a good level of health with drain punch
Azumarill with ability huge power and held item sitrus berry, with moves belly drum, play rough, liquidation and protect/aqua ring
A similar concept to iron hands however you rely on sitrus belly and aqua ring for healing
Annihilape with ability defiant, held item of your choice (I would go sitrus berry) and moves bulk up, rage fist, close combat (for power only - unfortunately doesn't activate defiant) and either substitute or protect (or a coverage move such as acrobatics if you prefer)
You use bulk up a few time whilst rage fist powers up from you taking hits, then substitute (if appropriate) and spam rage fist
Apologies for not using the correct format for Pokemon/movesets, I am new to the site and haven't figured it all out yet
