Brotato

More than a guide this is advise. Negative HP regeneration does not drain your HP, so do not worry about ever getting -HP Regeneration, especially if you already have weapons/items that give you Life Steal.

Do not worry at all about getting this achievement. It is almost a guarantee that you will end up getting it in your run with Fairy as Fairy has a -2 HP Regeneration modifier for every different Tier IV item you have. Therefore, I highly recommend that you do not compromise your runs in order to get this achievement. Winning a run with Renegade will unlock Fairy by the way. To be perfectly clear, Fairy is an item.



If you do not want to wait until you begin a run with Fairy, then simply accumulate enough items that give you negative HP Regeneration. Some items include Broken Mouth (-1 HP Regeneration), and Hedgehog (-1 HP Regeneration). Also, do not try this achievement with Chunky as he has a modifier where HP Regeneration modifiers are reduced by 50%, meaning that you will need to accumulate double as much negative HP Regeneration with him. Do not try it out with Lich, as he gets a +10 HP Regeneration starting modifier.