Top 9 in Top 10 smartest characters in anime Dr.Stone.
Despite being an old man in the Stone World, Kaseki's ability is one of the essential skills in the Kingdom of Science, he is the only one who can make flawless crafts. Compared to the others, Kaseki has no knowledge of science, but is trustworthy when it comes to crafting.
Kaseki has been by Senku's side from the very beginning. With Kaseki's help, the Kingdom of Science gradually took shape. Kaseki's greatest challenge is old age. Therefore, losing him in would certainly have a huge impact on the entire Kingdom of Science. Kaseki's knowledge is what makes him truly a genius craftsman