Cast Here Comes a New Hero! by paying {7}{U}, causing a player to draw five cards and create a token copy of Mirror-Mad Phantasm.
Activate the Mirror-Mad Phantasm token by paying {1}{U}, shuffling the token into your library and milling your entire library due to it not having a card named Mirror-Mad Phantasm in it.

Infinite self-mill

Mirror-Mad Phantasm

Here Comes a New Hero!

Activate Thunderclap Drake by paying {2}{U} and sacrificing it.
Cast Here Comes a New Hero! by paying {5}{U}{U}, targeting Biovisionary.
Thunderclap Drake triggers, copying Here Comes a New Hero! at least twice, with all copies targeting Biovisionary.
Resolve all Here Comes a New Hero! spells, creating at least three copies of Biovisionary and causing a player to draw nine cards.
At the beginning of your end step, each Biovisionary triggers, causing you to win the game.

Win the game

Biovisionary

Thunderclap Drake

At the beginning of your precombat main phase. Summon: G.F. Cerberus triggers, putting a lore counter on it and triggering its third chapter ability, copying the next instant or sorcery spell you cast twice.
Cast Here Comes a New Hero! by paying {5}{U}, targeting Biovisionary.
Summon: G.F. Cerberus triggers, copying Here Comes a New Hero! twice, with the copies targeting Biovisionary.
Resolve all Here Comes a New Hero!s, copying Biovisionary three times and causing a player to draw nine cards.
At the beginning of your end step, each Biovisionary triggers. Resolve the first trigger, causing you to win the game.

Summon: G.F. Cerberus

Cast Here Comes a New Hero! by paying {5}{U}, targeting Biovisionary.
Holding priority, activate Echo Mage by tapping it, copying Here Comes a New Hero! twice, with both copies targeting Biovisionary.
Resolve all Here Comes a New Hero! spells, creating three token copies of Biovisionary and causing a player to draw nine cards.
At the beginning of your end step, each Biovisionary triggers. Resolve the first trigger, causing you to win the game.

Echo Mage

Cast Here Comes a New Hero! by paying {6}{U}, 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}{B}. 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.

Infinite creature ETB

Infinite creature LTB

Infinite death triggers

Carnage, Crimson Chaos

Activated Sleeper

Cast Here Comes a New Hero! by paying {8}{U}, causing a player to draw six cards and creating a token copy of Bellowing Aegisaur.
Activate a mana-producing permanent you control by tapping it, adding at least {G}.
Activate Wayta by paying {G} and tapping it, causing Cacophodon and the nontoken Bellowing Aegisaur to fight each other, with each only taking 1 damage due to Temple Altisaur.
Cacophodon and Bellowing Aegisaur each trigger twice.
Resolve all Bellowing Aegisaur triggers, putting two +1/+1 counters on each other creature you control.
Resolve both Cacophodon triggers, untapping the mana-producing permanent and Wayta.
Repeat from step 2, alternating between having the token and nontoken Bellowing Aegisaur fight Cacophodon.

Combos with "Here Comes a New Hero!"