The will of the Moon Tree could be said to be strong, but it could also be said to be weak at the same time.
As the loser of the war, it had been suppressed, only while the seven Gods weren't present would it be able to take advantage of certain loopholes to sneakily manipulate a few things.
In the outside world, when the will of the Moon Tree wanted to influence Farnate who carried the elven bloodline, it needed Negary to hypnotize him before it could perfectly control him.
In other words, the current will of the Moon Tree was actually a complete weakling, there were very crucial reasons why it managed to make such bold moves.
Firstly, it was due to Chromie's Protagonist Aura, which allowed the will of the Moon Tree to easily influence him.
Secondly, Eternal Heat's tacit agreement and even partial support.