When clicked, this item removes the AA "Item: Firefist" 0/3 from the Special tab and replaces it with the following AAs:
"Item: Aura of Rage" 2/3
"Item: Disable Item Abilities 1/1
If you make a hotkey for the latter, it reads "Disable Effects". Clicking it removes the Item: Aura of Rage 2/3 and replaces it with the Item: Firefist 0/3 again.
This is on the Yelinak server. Looks like this is different than what was on Phinigel back in 2017.