Talk:Heavenly Emperor Kanon/@comment-114.108.234.234-20150624023622/@comment-66.231.154.74-20150625170616

Atk/Def Derease ailments are scripted differently from your standard ailments (i.e. Poison/Curse/Injury/Weakness). They were introduced much later in the game (I think with Fiora batch). However, every unit with status cleanse after that batch (Rigness batch onwards) can remove them, although no one can prevent it. All 7 star cleansers can remove Atk/Def down, as well as Rigness, Elmedia, and Arbonella, in global. However, we don't know if Gumi will eventually make it so that all cleansers are equal. Preventing Stat Down is nebulous; there may never be a nullifier for it.

So, tl;dr yes, everything Rigness Batch onwards can cleanse Atk/Def Down, but can't prevent it.