Peregrine Drake + Venser, Shaper Savant + Panharmonicon

Peregrine Drake
Venser, Shaper Savant
Panharmonicon

Requires
Panharmonicon on the battlefield. Peregrine Drake and Venser in hand. You control lands that can produce at least 3uu. 4u available.
Steps
  1. Cast Peregrine Drake by paying 4u
  2. When Peregrine Drake enters the battlefield, it triggers itself twice due to Panharmonicon
  3. Resolve one Peregrine Drake trigger, untapping five lands
  4. Activate those lands by tapping them to add at least 3uu
  5. Resolve the remaining Peregrine Drake trigger, untapping five lands
  6. Activate those lands by tapping them to add at least 4u
  7. Cast Venser by paying 2uu
  8. When Venser enters the battlefield, it triggers itself twice due to Panharmonicon, returning itself and Peregrine Drake from the battlefield to your hand
  9. Repeat
Results
Infinite mana lands you control can produce. Infinite ETB. Infinite LTB. Infinite storm count.