Cast Sensei's Divining Top by paying 0 due to Heliod
When Sensei's Divining Top enters, Rook Turret triggers.
Holding priority, activate Sensei's Divining Top by tapping it, causing you to draw a card and put Sensei's Divining Top on top of your library.
Resolve the Rook Turret trigger, causing you to draw Sensei's Divining Top from your library, and then discard a card other than Sensei's Divining Top.
Repeat
This loop relies on Heliod, the Radiant Dawn // Heliod, the Warped Eclipse to drastically reduce mana costs, dropping Sensei's Divining Top down to a free cast. Once the artifact enters, Rook Turret triggers to let you loot by drawing and discarding. By tapping Sensei's Divining Top in response to that trigger, you safely tuck it back onto your library just in time to draw it off the Rook Turret effect, setting up a continuous cycle that generates endless card filtering and a massive storm count.