@hall3
he'll struggle in his 2nd fight against hinata, but thats it. He maybe had a tough time against chronoa but thats because he had to keep the others in check without killing chronoa. Rimuru isnt all for fights in the LN, he rarely does it. His subordinates fight a lot. But rimuru will have some skirmishes here and there with yuuki and he will keep powering up in the form of his subordinates getting stronger. The turning point of his opness was when he named wisdom king raphael and defeated velgrynd and veldora (mind controlled) at the same time and evolved to a draconic slime, basically an existence similar if not equal to a true dragon. So yeah if you ask if he will hit a brick wall, no, at least not yet i think. When he hits a wall in his progress, raphael sensei would take care of it.