From the looks of this Slime King, it seems to be much bigger and powerful compared to the one in the sewer. Perhaps the card got a higher quality King Slime...
@Herico She only knows things from the books she had read, and not much from real-life dangerous situations. It's like having a librarian in a war instead of a battle mage that's both knowledgeable and experienced in dangerous situations.
Isaac Newton and Albert Einstein's personalities are swapped. In the real world, it's Albert that has the joker personality, while Isaac is the more strict and serious one.
He solved the "Ruler of the Demonworld" problem. He was having issues of being coerced by the devil girl on being the new ruler, but things turn for the better in the end for the MC lol