The MC's initial weaknesses were a lack of direct damage and lack of elemental (primarily fire and ice) resistance. That makes sense as a grass/plant type. He asks his teacher, should I dedicate my next rings to patching up these weaknesses? Grandmaster says no, that if he does that, he would be sacrificing the opportunity to improve his strengths. So what do you know, before he even needs to fight the fire and ice schools, he comes across 2 one of a kind herbs that strengthen his body, make him immune to fire, ice, and most poisons, and improve his spirit power. He doesn't have to give up anything and gets everything he needs. His spirit starts as the weakest blade of grass but evolves after leveling up enough into a top tier spirit. I love Magikarp power characters, but doing it this way sucks. What is even the point of setting up rules that the MC doesn't need to follow?
Check out all this BS:
gave him back his memories.