These are my results testing minions who trigger decrepify CDR, which is a lucky hit proc:
shadow mage (1) - no
shadow mage (2) - no
ice mage (1) - no
ice mage (2) - no
bone mage (1) - no
bone mage (2) - no
Skirmisher (1) - no
Skirmisher (2) - no
Defender (1) - yes (ok)
Defender (2) - yes (ok)
Reaper (1) - yes (good)
Reaper (2) - yes (good)
Bone golem (1) - yes (bad)
Bone golem (2) - yes (bad)
Blood golem (1) - Maybe (but very bad)
Blood golem (2) - Maybe (but very bad)
Iron golem (1) - Maybe (but very bad)
Iron golem (2) - Maybe (but very bad)
The golems mostly attack too slow to be worth it, and there is only 1.
Adding my own anecdotal information to this, obviously people would be wise to check for themselves.
I believe it’s only the wind up attack specifically on the Reapers that can trigger Decrepify’s CDR. Don’t ask me why, and it’s kinda hard to gauge without a target dummy but might wanna look into it. Their regular auto attacks don’t appear to (?).
I gave the Iron Golem a spin and I can’t say that I ever noticed its active skill (stun slam) trigger it. Likewise, its passive Shockwave with version 1 didn’t seem to trigger it either.
This class is legitimately held together by duct tape and the single digit dev hours of the guy responsible for cramming it in at the last minute.