Michael ignored the fight in his head. Instead of joining them, he focused on the knowledge he'd procured about the Seal Fusion technique. Eren's intent had been infused into the Seal Fusion technique, which was helpful as it increased Michael's understanding to a certain extent.
He tried using the technique only to hear the World Serpent speaking to him again.
[While that white-haired guy's words are true, your Seals will weaken if you don't grant your Curse bits and pieces of control.]
Michael frowned but continued listening.