It wasn't that he couldn't push forward, but that pushing forward equated to death, leaving almost no hope of reaching the ultimate level.
This act of severing Tuoba Ancient God's future path was Lin Yuan's way of settling the score from being wronged before.
Fang Qing, his good friend, also virtually died at the hands of Tuoba Ancient God. Even though revived by a Supreme Being, the animosity was established.
If Lin Yuan had the capability, naturally, he wouldn't let the other party off.
Next were the three strange items acquired, which enhanced Lin Yuan's strength in all aspects.
Defense, attack, coupled with the 'Premonition' from the bronze Compass, almost made Lin Yuan a hexagon warrior with no weaknesses.
If he could develop the capabilities of the silver mirror, employing spatial strategies, then Lin Yuan could completely traverse this Two-dimensional World with ease.