Asta winds up being the only member of the Royal Knights who doesn't get a robe capable of fitting him, thanks to the addition of more members than they thought would be joining, and the lack of special fabric for the Royal Knight robes, which offer additional magic protection.

What episode does Asta become a royal knight?

"Black Clover" The Royal Knights Selection Test (TV Episode 2019) - IMDb.

Who wins the Royal Knights in black clover?

After a fantastic battle between the Azure Deer Captain Rill's team and Yuno and Noelle's team, the winner of the Royal Knights selection tournament was revealed to be the team of Yuno, Noelle, and shy newcomer En.