Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight | Jet, Freedom Fighter

Effects that Alter a Creature's Power/Toughness (Anthem Effects)

Cards

All permanents on the battlefield (
Eirdu as
Isilu, Carrier of Twilight and
Jet without a -1/-1 counter on it).

Activate
Phyrexian Altar by sacrificing
Jet.
When
Jet dies, its persist ability and second ability trigger.
Resolve the second trigger, putting a +1/+1 counter on
Hex Parasite and another creature you control.
Resolve the persist trigger, returning
Jet from your graveyard to the battlefield with a -1/-1 counter on it.
When
Jet enters, its first and second ability triggers, dealing damage to a creature an opponent controls.
Activate
Phyrexian Altar by sacrificing
Hex Parasite, adding ({1} magic symbol) .
When
Hex Parasite dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
Activate
Hex Parasite by paying ({1} magic symbol) ({B} magic symbol) , removing the -1/-1 counter from
Jet.
Repeat.

The anthem must boost
Jet's toughness by 1 or more each iteration so it doesn't die due to having 0 toughness when it enters with a -1/-1 counter on it. You can also sacrifice another nontoken creature and use the second +1/+1 counter to counteract the -1/-1 counter on that creature. This loop can also be performed whenever an opponent controls a creature to destroy that creature.

This combo has been estimated to be Spicy (Bracket 3-4+).