I still don't think Corrin is that great, but Mkleo is simply built different
Corrin is the metagame's biggest badly kept secret. Corrin's had a bad reputation to the general playerbase for a while, but whenever you see a top player try our Corrin, you hear the same thoughts, "How can this character be bad? Seems good to me." Whether it's ESAM or Nairo or Zackray or Cosmos or Leo, top players seem to judge Corrin well by instinct alone. They frequently dismiss these gut reactions, though, when placing her on a tier list. Nairo will say, "Well, maybe it's just my experience with playing her in smash 4" or Zackray will say "but I haven't devoted much time to her, so maybe I'm wrong."
But imo they weren't wrong, and Corrin is really that good.
Corrin may look slow, but Corrin has great mobility tools in pinkicks and a fast dash-to-shield. How fast you can shield out of a dash in this game depends on your character; it takes Ganondorf 15 frames to shield after initiating a dash, while it takes Roy, ROB, and Palutena 10. It takes Corrin
7. She's tied with Sheik for fastest dash-to-shield in the game. Not typical for low-mobility characters.
This fast dash into shield couples well with an array of OOS options (three fast and big options in f-air/n-air/up-air, and two slower but stronger ones in up-smash and up-b), which means you have to second-guess yourself when weaving around grounded Corrin.
Corrin's jump stats are good. You generally want bigger full hops and smaller short hops, since bigger full hops let you get out of disadvantage faster and smaller short hops let you mix up your landing aerials better. Corrin has a full hop height of 33 and a short hop height of 16, much better than Ike's 29/16 and actually even better than
Cloud's (32.5/17)! At RETA, we saw MKleo double jump out of the corner several times with Corrin against sparg0's Cloud. You would rarely see the same situation with Byleth.
Corrin has a much easier time landing than most, or basically all, sword characters, including the likes of Lucina (who has much better air mobility on paper) and Byleth. In addition to d-air and n-air, coverage that similar characters don't have, Corrin can b-air and fastfall on the first active frame of b-air, giving her horizontal and vertical landing burst in one.
Looking at Corrin's stats in this way, I'd actually suggest that Corrin's overall mobility is above average rather than subpar.
Then in advantage, Corrin has:
- Some of the best ledgetrapping in the game, with kill confirms out of n-air, and pin mixups; d-smash will lethally catch neutral getup and can cover roll
- Some of the best juggling in the game. Leo's said it himself: Corrin's up-air just wins games for you. It's so big that if you try to airdodge past it you can get b-aired for the stock, and it's one of the main reasons that Corrin is better than Byleth against Falco (Byleth's up-air can't juggle Falco nearly that well).
- Some of the best and most consistent combos at all percents, with minimal execution barrier
- A kill throw
All that really leaves is neutral normals, and the stats there speak for themselves. Corrin's up-air is -5 on shield, f-air is -4, and n-air is -7. Those are really good stats to boast on moves that are so big. b-air is -7/-8 too and is one of the safest aerials in the game thanks to the pushback. d-tilt being f5 just makes Corrin so easy to space with, and almost every spacing move leads to more guaranteed damage almost immediately.
It just ties so well together. You're contending in neutral with the likes of Diddy and Cloud and then juggling and ledgetrapping for 60+% and then kill confirming for the stock. If you mess up, you still have plenty of leeway in disadvantage. Seems very evident that Corrin should have some great matchups.