Gu Mengmeng realized afterwards that it was thanks to Wabei's help that her sons had all evolved.
The method was simple and crude. He had just dragged them out everyday for a beating…
Males get promoted after accumulating enough battle experience. Lea's three to five years was made with the conservative assumption that they would only be battling wild animals during their hunts.
Actually Elvis and Lea could also carry out that type of training with them—but Gu Mengmeng cared too much for her three sons, so they would subconsciously hold back during their training, rendering their attacks ineffective as battle experience.
It was different for Wabei. Snakes were characteristically cold-blooded and the act of showing mercy… he had no idea how to.
He did not go soft at all on those three little ones.