Kykar triggers, creating a 1/1 Spirit creature token.
When the Spirit enters, Mana Echoes triggers, adding C for each Spirit you control.
Activate Trusty Boomerang's equip ability by paying 1, attaching it to the Spirit token.
Activate the Spirit token by paying 1 and tapping it, tapping a creature a returning Trusty Boomerang from the battlefield to your hand.
Repeat.
This clever loop gets its engine running by casting Trusty Boomerang, which immediately prompts Kykar, Wind's Fury to produce a Spirit token. That fresh arrival triggers Mana Echoes to flood your pool with colorless mana as the shared creature type multiplies, while Tyvar, Jubilant Brawler steps in to grant the newly equipped Spirit the necessary speed to act immediately. By using the Spirit token to activate the returned Trusty Boomerang's bounce ability—subsidized by Kykar, Wind's Fury's ability to sacrifice a Spirit for red mana when needed—you can continuously replay the Equipment to repeat the entire cycle.