Carnage, Crimson Chaos | Activated Sleeper | Rukarumel, Biologist (and one other card)

Cards

({1} magic symbol) ({W} magic symbol) ({U} magic symbol) plus ({2} magic symbol) ({B} magic symbol) if
Activated Sleeper is in your hand available.

Cast
Sygg's Command by paying its mana cost, creating a token copy of
Carnage.
Put the nontoken
Carnage into your graveyard due to the legend rule.
When the
Carnage token enters, it triggers, putting
Activated Sleeper from your graveyard onto the battlefield, or another applicable card otherwise.
If
Activated Sleeper was not returned in step 3, cast it by paying ({2} magic symbol) ({B} magic symbol) . Regardless, choose to have
Activated Sleeper enter as a copy of
Carnage.
Put
Activated Sleeper into your graveyard due to the legend rule.
When
Activated Sleeper enters, it triggers, returning itself from your graveyard to the battlefield as a copy of
Carnage.
Repeat from step 5.

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