Michael's eerie appearance and smile were more than enough to convince the remaining Lords of the Divine Alliances to accept his conditions. He didn't think about signing a Soul Pact with them because his soul was still too taxed for his own good. If the Divine Alliances' Lords were to die, the Soul Pacts would shatter, and that would hurt his soul a little. Michael wished to avoid that scenario for the time being, if possible.
With that in mind, Michael told the Lords of the Divine Alliances to sign a deal with the Primordial Tree Spirit. The Primordial Tree Spirit was still the core of the Untamed Jungle. It controlled the primal root and the smaller portion of the Nature Heart's Divinity. Michael wished to procure the Nature Heart in its entirety, but he was linked to the entire Untamed Jungle because of his firm connection with the Primordial Tree Spirit and its primal root in the first place.
