@notlazy He is upset about 1 of 2 things based on clues:
1 ) he knows the place they fell and was in on it, so now he is upset cause that means things went down the drain. More then likely he was jelous of magicians and was in on the expirement to turn himself into a hominclus with high tier magic.
2 ) He wanted pram to grow due to the loss of his friends, and his friends coming back means pram wont grow as fast as he likes