Spirit Cage: MC Physique Begs Mai Duo to Take Him in After Demolishing the Tower

[Single heroine Mai Duo + MC system + upgrade and romance + no spoilers for the protagonist] The protagonist Tianqi, originally a college student, accidentally traveled to the world of "Spirit Cage" and became the bottom-level dust citizen 4399 of the lighthouse. The MC system has also been awakened, and you can gain experience points by killing targets, which can be used to redeem items in the cube world to improve PVP, parkour, quick construction and other abilities. As a commoner, he was bullied and abandoned randomly, which made Tianqi gradually close his heart and only seek to protect himself. After exchanging experience points for the world map, he discovered that there were other survivor organizations on the ground, and the settlements became more prosperous. Then the fire of revenge was ignited. He summoned withered skeletons to cause chaos in the lighthouse, used a potion of slowness and weakness to retaliate against the light bearer, and took advantage of the chaos to take Ran Bing and Mark with him and escape from the cage with elytra. But they never thought that on the way to Dragon Bone Village, the three of them were attacked by the Devouring Beast. When they were about to die, Tianqi was rescued by Mai Duo. While getting along with the kind-hearted Mai Duo, he got out of the shadow of betrayal. After that, Tianqi worked side by side with Mai Duo and his partners in Dragon Bone Village to fight against Mana Ecology.