In this way, as long as that Treant can reasonably use its Strength, then given the Advantage of its size at that time, not only can it prevent Zhou Tian and his team from leaving, but it could have easily killed these Invaders if it wanted to.
However, clearly, judging from the Treant's Performance at that time, although it indeed had the Ability to easily kill Zhou Tian and his team, it didn't have the intention to do so.
Even though it was constantly attacking Zhou Tian and his team, the Treant's Performance at that time seemed, in every aspect, like it was only acting on instinct, much like other plants. Under those circumstances, even though the Treant's Strength hadn't changed, the Threat to Zhou Tian and his team was certainly much smaller than if the Treant had a strategic plan.
And since the Treant did not possess high Wisdom, it was naturally not as difficult for Zhou Tian and his team to plot against it.
