Saheeli's Artistry | Donnie & April, Adorkable Duo

Cards

You control up to seven lands that can tap to produce at least ({4} magic symbol) ({U} magic symbol) ({U} magic symbol) .

Activate up to seven lands by tapping them, adding at least ({4} magic symbol) ({U} magic symbol) ({U} magic symbol) .
Cast
Saheeli's Artistry by paying ({4} magic symbol) ({U} magic symbol) ({U} magic symbol) , creating a token copy of
Great Whale that is an artifact.
When the
Great Whale token enters, it triggers, untapping up to seven lands.
Cast
Donnie & April by paying its mana cost.
When
Donnie & April enters, it triggers, returning
Saheeli's Artistry from your graveyard to your hand.
Activate up to seven lands by tapping them, adding at least ({4} magic symbol) ({U} magic symbol) ({U} magic symbol) .
Cast
Saheeli's Artistry by paying ({4} magic symbol) ({U} magic symbol) ({U} magic symbol) , creating a token copy of
Donnie & April and the
Great Whale token.
Put the
Donnie & April token into your graveyard due to the legend rule.
When the
Donnie & April and
Great Whale tokens enter, they trigger.
Resolve the
Donnie & April token's trigger, returning
Saheeli's Artistry from your graveyard to your hand.
Resolve the
Great Whale token's trigger, untapping up to seven lands.
Repeat from step 6.

If the seven lands can tap to produce ({5} magic symbol) ({U} magic symbol) ({U} magic symbol) or more, this combo will net infinite mana. So long as you produce an extra ({U} magic symbol) each loop, you can eventually stop copying
Great Whale and copy other creature(s) or artifact(s) instead. You can also create two copies of
Donnie & April instead to return other applicable cards to your hand.

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