Lol, it's a funny conversation. Even the creator of One Piece Eiichiro Oda begged him to be nicer to his poor brother. I think this happened at one of the Q&As that he regularly answered the readers' questions. His brother was apparently so scared of his glare Be nice to your siblings!
Speaking of the beard or mustache, the first character that popped out of my mind was Dracule Mihawk! It has been a while since we saw Mihawk in the anime series as the story is focusing on the Wano. The last time he appeared was when the Navy set out the expeditions to hunt down the Warlords. I really wanna see how a bunch of Navy minions with a few ships without an admiral can deal with one of the most dangerous men in the world of One Piece That's basically suicide.