When Guildless Commons enters the battlefield, it, The Necrobloom, and Kodama of the East Tree trigger.
Resolve the Kodama of the East Tree trigger, choosing not to put anything from your hand onto the battlefield.
Resolve the Guildless Commons trigger, returning it from the battlefield to your hand.
Resolve the The Necrobloom trigger, creating a token.
When the token enters the battlefield, Kodama triggers, putting Guildless Commons from your hand onto the battlefield.
When Guildless Commons enters the battlefield, it and The Necrobloom trigger.
Repeat from step 4.
This elegant loop spins up a self-sustaining engine built entirely around the recursive bounce of Guildless Commons. As that land enters, it triggers Kodama of the East Tree and generates a token thanks to The Necrobloom's landfall ability. That newly created token's entry triggers Kodama of the East Tree once more, allowing you to seamlessly drop Guildless Commons right back onto the battlefield from your hand while the land's own bounce trigger returns it to your hand in response.