I love how Rouxls Kaard has the “self-assured dumbass bad at making puzzles” of Papyrus, the flamboyance of Mettaton, but the award for most similarities goes to noted high-strung, equally flamboyant dumbass who also stank at making puzzles Magic Brian, from TAZ, an unrelated intellectual property.
There are alot of great lines in deltarune but none beat out when ralsei gives susie advice on complimenting people by saying “just tell them something you wish people would say to you” and susie responds with “you are unbanned from free ham sandwich day”