Activate Sensei's Divining Top's second ability by tapping it, causing you to draw a card and put Sensei's Divining Top from the battlefield onto the top of your library.
Cast Sensei's Divining Top from the top of your library by paying 1 life.
When Sensei's Divining Top enters the battlefield, Leonin Elder triggers, causing you to gain 1 life.
Repeat.

Infinite card draw

Near-infinite storm count

Near-infinite lifegain triggers

Infinite draw triggers

Sensei's Divining Top

Leonin Elder

Bolas's Citadel

Gain life.
Heliod triggers, putting a +1/+1 counter on Scurry Oak.
Scurry Oak triggers, creating a creature token and an artifact token.
When the artifact token enters the battlefield, Leonin Elder triggers, causing you to gain life.
Repeat from step 2.

Infinite ETB

Infinite lifegain triggers

Infinite lifegain

Infinite creature tokens

Infinite Food tokens

Infinite +1/+1 counters on a creature

Peregrin Took

Heliod, Sun-Crowned

Scurry Oak

Gain life in any way.
Scurry Oak triggers, putting a +1/+1 counter on itself.
Scurry Oak triggers, creating a creature token that enters the battlefield as an artifact due to Mycosynth Lattice.
Leonin Elder triggers, causing you to gain life.
Repeat from step 2.

Light of Promise

Mycosynth Lattice

Archangel of Thune triggers, putting a +1/+1 counter on each creature you control.
Archangel of Thune triggers, putting a +1/+1 counter on Scurry Oak.
Scurry Oak triggers, creating an artifact creature token.
Leonin Elder triggers, causing you to gain 1 life.
Repeat from step 2.

Infinite +1/+1 counters on creatures you control

Archangel of Thune

Biotransference

Combos with "Leonin Elder"