Scarab of Eternity

Unrivaled

Attach [Kheprius]: UUUU - Reduce the attach cost by U for each Scarab Counter on Clash cards you don't control.

While this card is attached, it gets "Action: Put a Scarab Counter on target Clash card you don't control".

Attached card gets +1/+1 and, "Trigger - Attack: Detach an attached Scarab of Eternity. This gets +1/+0 for each Scarab Counter on Clash cards you don't control until the start of your next turn".