I'll just paste my YouTube comment here as a reminder (plus, some new things I've noticed.)

Not very great, it's not terrible, but it seriously needs some updating.

The things I noticed:

- CLSNs have infinite priority (the hurtbox stays on the character during normal attacks, but the hitboxes extend far beyond them.)

- Throw sprites are not aligned properly (5XX1 isn't positioned at midsection, 5XX2 isn't positioned at neck.)
- This is generally important as if Sylveon is getting thrown, it'd look extremely off .

- Normals come out too quick (some CLSN1 literally come out the very first frame.) And generally some janky animations.
- One of the normals launches the character really high up for an easy juggle.

- Spritework could need more polish, some more frames, etc.
- One of her normals has a smear/movement frame, but nothing without the smear effect. Looks very off.

- Mystical Fire can be spammed with little punishment.

- Despite her level 1 and level 2 being far reaching multihits (and in general are really similar moves with range differences), her level 3 is a projectile that can be easily jumped over; and is vastly inferior compared to her other two supers.
- Her level 1 has just enough pushback to not really be reliable, and considering her level 2 is a very similar move; it is pretty invalidated unless you're desperate.

- Swift EX and Moonblast send the opponent extraordinarily high up on hit.

- Moves have crazy amount of blockstun, which the AI heavily abuses.

- Leafeon assist is just it coming up and preforming one of Sylveon's normals. Could be fitting if it were a more unique attack, maybe one Leafeon can preform?

- Intro timing isn't correct on the evolving intro; announcer cuts off the voiceline.
- I theorise that the state to cut off the intro is when the animation reaches a certain point, but the voiceline continues after that point.

- Her -1 statedef code doesn't prioritise her specials and supers command states which causes the character to not preform moves consistently when controlled by human.

- Some compatibles are broken.
- Passare isn't timed correctly.
- Ink has a frame missing.
- Midnight Bliss grab frames aren't positioned at the neck.
- Pitfall, Top Spin, and Wedgied do not have any assigned sprites and thus, show up as blank.
- Her King of Fighters 11 portrait doesn't have a solid fill background (which is puzzling because you took her other portraits from my Sylveon which does have a proper portrait for KOF 11.)