The story is great, the mars base and the robots etc. But the battles are boring. In the beginnning he used his machines and special time or space magic, but recently he probably needed to downgrade for his allies to still be usefull. So now he lets his hair glow, grow longer and just slaps his opponent with a less impressive version of going super saiyan. Luckily his allies specialize in slapping opponents so they can help him.
I think that its is getting to that point in OP-MC stories where the author tries to create some conflict that the MC can't immidiatelly fix himself. But since the MC is per definition OP it feels like false powerscaling where the MC suddenly starts talking about how powerfull the new enemy is, without the enemy actually showing us why he out of all enemies would be more powerfull.