There are usually 7-8 legendary skins. I'm going to put them from high (most deserved) to bottom (least deserved).
1.Lifeline – hasn't had a legendary event skin in 3 seasons. Only judge jury and that's it.
2.Wraith – last 2 seasons, she only had epic skins and her witch skin wasn't exactly a banger even tho is was 🔥
3.Revenant – Last season he didn't get a skin. Usually give skin after 1st season.
Loba – no sick skins yet, revenant still deserves a skin more than she does even though he just got a recolour.
Crypto – only 2 skins so far (from events) and not many recolours and limited skins
Caustic – got three skins (events) but not many recolours and not many limited skins
Mirage – got three skins (events) and some sick recolours but deserves to be on the list cuz it's his heirloom this season.
Bangalore (if theres an 8th option)- she has been in many events and had many limited skins but her skins aren't great over all. Needs a good skin asap as this hero was here from the beginning of the game (not saying her current skins are trash)