He pretty much needs to reset now before anything happens that prevents him from reseting back to the start, BUT even if he does he still lacks the strength and she will still be in a lot of danger. In a way it may be best for him to go with isaacs plan for now and get the lulium since he can take that back with him when he resets. In fact, it would be best if he betrayed his allies and took ALL of the lulium and then killed himself to reset back to the start. With that much power he would stand far better odds against these 'new' powerful enemies fueled by a ton of lulium. He also needs to find that female necromancer again to find out what she knows and to get a power up for those skills. Raising an army of the undead to fight the other nation would be OP and she may know a way to raise his skill level faster.