Drake went serious after he had made up his mind to kill Liu Kai.
He doesn't want to neglect his feeling of getting jealous of Liu Kai's exceptional talent now, so he reached the conclusion that he wouldn't allow him to live the day when he already surpassed him.
Before he chose his Path, he's a nobody in his clan.
Nobody cared about him.
He began training at his own will without a proper master and guidance.
With a little to no help, he managed to be on the average level candidate.
And after getting his hands on a small number of elixirs, he easily surpassed everyone in his Tribe.
From being a nobody, they treated him special.
A kid with a one in a million talent on being transcendent.
After seeing his rapid growth, the Patriarchs in his clan solely focus on him.
The attention that he's not used to gave him joy and he wholeheartedly embraced it rather than being treated like a nobody.