High fall speed matched with a fast, and small hitbox recovery means that edge guarding robin can be quite finicky. recovery is good for edge guarding as well (If you know what you are doing), using arcfire can trap opponents and can lead to multiple combos, [arcfire to side air or down air (Levin, or down smash if lucky with hitboxes) something I find useful is a strange follow up option that is arcfire to first stage side b. Also, pretty much every smash player should know this but in ultimate, the hitbox for Levin down smash is massive. it hits behind, over ledge, and launches horizontally, (Sorry Little Mac) and makes a great edge guard. many people say this character is bad, and he is... in the wrong hands. I like to say finicky characters are for finicky people. also, don't use nosferatu, its bad, frame data and end lag are quite long, and the move barely does anything.