Overview
Dark Pit is an evil angel from the Nintendo classic, Kid Icarus. In SSBU, he is a lightweight character with at least 3 double jumps. He is great for edge guarding and can launch opponents pretty high with his Electrodash Arm.
Strategies
Dark Pit has many edgeguarding opportunities, along with many launch options. His combos are the same as Pit's
Silver Bow
With his neutral special, Dark Pit is probably the best edge guarder in SSBU. He can aim where exactly the arrow goes, making it perfect to hit enemies over the edge. This is similar to Ness and Lucas's PK Thunder, except maybe a little less controllable.
Electrodash Arm Combo
Here's a good combo that uses the Electrodash Arm: Start with the Silver Bow to make them flinch, then use the forward tilt, follow up with the forward smash, then hit the opponent with the side special. You can also follow up with a mid-air side special to launch opponents farther. You can chain the side special as much as you can or want to.
Down Throw
All you really need to do with the down throw is use it on the edge. Otherwise, it's not exactly useful.
Electrodash Arm
Honestly, Electrodash Arm is a very useful launch tool on it's own.