Sil had made the decision to give one last gift to Quinn. Even if it was to take up all of the MC cell's in his body. Of all the images in his head, he was trying to think of someone that he could summon that might be of some use while still being powerful.
That's when Sil had discovered someone who would take up more MC cell's then it should have done. That was Arthur. Ever since his passing, not for a single moment had the word of Arthur and weak been in Quinn's mind.
In fact, the beating that he had received from Arthur at the time, all of the pain he had suffered, was a mental scarring on him that would stick with him forever. Which was why the Arthur that had been summoned, was far stronger than that of the original Arthur.
Of course it had its limits, otherwise Sil would have never have been able to summon him.