When Triskelavus dies, its persist ability triggers, returning it from your graveyard to the battlefield with two +1/+1 counters on it.
Activate Triskelavus' first ability twice by paying ({2} magic symbol) and removing two +1/+1 counters from it, creating two 1/1 Triskelavite artifact creature tokens.
Activate Clock of Omens by tapping Triskelavus and a Triskelavite, untapping Cauldron of Souls.
Repeat.
Once you have infinite Triskelavite tokens, you may sacrifice them to deal infinite damage to any target(s).