a lot of characters can do corner to corner combo, although some requires assists. with dorm and doom, if you launch with hidden missiles called at the same time, you can do a basic mmhs combo and the missile will otg and let you get a easy relaunch. basically anyone that can do relaunch can do corner to corner.
zero is the best character and has easy corner to corner combo. but the lightning loop need some practice. wesker can also do corner to corner combo with qcf l, teleport forward and otg with assist and launch.
spencer can do corner to corner combo solo and deals well over 800k with missiles. with dorm and doom assist dont do that much for him, missiles can help him maul someone but he cant protect the missiles well. magneto can also do almost corner to corner solo, but you get no damage if you dont end with hyper grab into tempest. modok probably has the easiest corner to corner combo, but he is a hard character to play.
vergil dont really have a corner to corner combo, but he doesnt need it since his s.h hits half screen and he is the second best in the game, untouchable with meter. you will have to learn some set-ups and mix-ups with him to be effective.
dante also dont have any corner to corner combo, but he is still a strong point and assist character. you have to learn his basic bold cancel bnb to be effective, since his old easy relaunch combo dont work anymore.
i would say if you are going to practice more, i would play someone like zero and dante. but if you dont play that much and still wants to be effective then wesker, nova is your man
vergil is kind of in between since he can play really dumb and be good with just teleport and assists. but some of his stuff is unsafe and the sword loop need some practice.