Raynor, is auto attack based and a good range, has a heal when he gets low hp an attack speed steroid for self and allies and a knockback/finisher.
Valla(basically the demon hunter from diablo 3) , has 3 different build paths, ultra auto attack based, single target spell based or aoe spell caster based. I personally go the aoe purely because theres lots of teamfighting in this game! she has a single target bouncing spell, an aoe multishot and a vault which is basically Vaynes dash but better.
Falstad, doesnt have a mount but can press his mount button to fly anywhere on the battlefield almost instantly. Hes more of a spell based ADC because his spells do crazy damage but his auto attacks arent too shabby either, think of him as a hybrid between lux and an adc. He has the big powerful beam cannon ult, a boomerang hammer which slows and dmgs, a lightning attack that damages enemies when youre near them and a long dash and shield on his E.
Tychus and Nova are also available but theyre not like conventional ADC's at all. And theres also Sgt Hammer and Tyrande which you could class kind of the same but again they're a bit strange.