If Oboro is on the battlefield, tap it for {U}.
Activate Oboro for {U}, returning it to your hand.
Play Oboro.
Field of the Dead and Kodama of the East Tree trigger.
Resolve the Kodama of the East Tree trigger, not putting anything onto the battlefield from your hand.
Resolve the Field of the Dead trigger, creating a 2/2 black Zombie creature token.
Kodama of the East Tree triggers.
In response to the Kodama of the East Tree trigger, tap Oboro for {U}.
Activate Oboro, returning it to your hand.
Resolve the Kodama of the East Tree trigger, putting Oboro onto the battlefield from your hand.
Field of the Dead triggers, creating a 2/2 black Zombie creature token.
Repeat from step 7.

Infinite creature tokens

Infinite ETB

Infinite landfall triggers

Kodama of the East Tree

Field of the Dead

Oboro, Palace in the Clouds

Activate Sakura-Tribe Scout by tapping it, putting Oboro from your hand onto the battlefield.
When Oboro enters the battlefield, Retreat to Coralhelm triggers, untapping Sakura-Tribe Scout.
Activate Oboro's first ability by tapping it, adding {U}.
Activate Oboro's second ability by paying {1}, returning it from the battlefield to your hand.
Repeat.

Retreat to Coralhelm

Sakura-Tribe Scout

Activate Scaretiller's ability from Paradise Mantle by tapping Scaretiller, adding one mana of any color.
Scaretiller triggers, putting Oboro from your hand onto the battlefield tapped.
Oboro enters the battlefield, triggering Retreat to Coralhelm, untapping Scaretiller.
Activate Oboro's second ability by paying {1}, returning it from the battlefield to your hand.
Repeat.

Scaretiller

Paradise Mantle

At the beginning of your upkeep, Second Chance triggers, causing you to sacrifice it and take an extra turn after this one.
Play Oboro from your hand.
Oboro enters the battlefield, triggering Emeria Shepherd, returning Second Chance from your graveyard to your hand.
Activate Oboro's first ability by tapping it, adding {U}.
Activate Oboro's second ability by paying {1}, returning Oboro from the battlefield to your hand.
Cast Second Chance by paying {2}{U}.
Repeat each turn.

Combos with "Oboro, Palace in the Clouds"