Orvar, the All-Form | Peregrine Drake | Seething Anger

Cards

You control up to five lands that can tap to produce at least ({3} magic symbol) ({R} magic symbol) .

Activate up to five lands you control by tapping them, adding at least ({3} magic symbol) ({R} magic symbol) .
Cast
Seething Anger with buyback by paying ({3} magic symbol) ({R} magic symbol) , targeting
Peregrine Drake.
Orvar's first ability triggers, creating a token copy of
Peregrine Drake.
When the
Peregrine Drake token enters the battlefield, it triggers, untapping up to five lands.
Resolve
Seething Anger, giving the nontoken
Peregrine Drake +3/+0 until end of turn and returning
Seething Anger to your hand.
Repeat.
If you control up to five lands that can tap to produce at least ({4} magic symbol) ({R} magic symbol) , this combo nets infinite mana, which you can then target any creatures you control in step 2 to create infinite token copies of them.