Ashnod's Altar | Nim Deathmantle | Drizzt Do'Urden (and one other card)

Cards

Activate
Ashnod's Altar by sacrificing Drizzt, adding ({C} magic symbol) ({C} magic symbol) .
Nim Deathmantle triggers.
Pay ({4} magic symbol) for the
Nim Deathmantle trigger, returning Drizzt to the battlefield and attaching
Nim Deathmantle to it.
Drizzt and
Dual Nature trigger.
Resolve the Drizzt trigger, creating a legendary Cat creature token.
Activate
Ashnod's Altar by sacrificing the Cat creature token, adding ({C} magic symbol) ({C} magic symbol) .
Drizzt triggers, putting a number of +1/+1 counters on Drizzt equal to the difference .
Repeat.
Once you have infinite
Dual Nature triggers on the stack, resolve each one, creating a token copy of Drizzt.
The token copy of Drizzt triggers.
The token copy of Drizzt is put into your graveyard due to the legend rule.
Resolve the Drizzt trigger, putting a legendary Cat token onto the battlefield.
Activate
Ashnod's Altar by sacrificing the Cat token, adding ({C} magic symbol) ({C} magic symbol) .
Repeat until there are no
Dual Nature triggers remaining.

This combo has been estimated to be Exhibition (Bracket 1+).