(starter) > 214L
Grimnir's meterless midscreen conversions are pretty average. Off very distant hits (including most whiff punishes) you can't even connect 214L. If your starter is autocombo, you can end on 214M instead for greater corner carry.
autocombo or 2M > 236H~8 > 214U > 2H > 623M > 2M > 214H (> 22L or 22H or 22U)
Your easiest (actual) midscreen combo. If you're dropping the 2M after 623M it's probably because you're doing the 2H too late. End on 22L or 22H if you reach the corner and wallbounce with 214H. End on 22U if you're a little bit spaced (it whiffs if you're too close) and you can do the 5U > j.6U > j.H fuzzy setup.
autocombo or 2M > 236H~8 > 214U > 22U > 5H > 623L > 9U > j.M > j.9U6U whiff > j.H fuzzy
If 214U takes you close-ish to the corner, you can spend three of your 22U seals to go into this easy fuzzy setup. You can do j.6U6U whiff instead to knowledge check with an empty low.
Listed below are midscreen setups you can do if you *won't* reach the corner. Midscreen fuzzies are generally harder, but the setups leave a lot of room to do goofy things and catch your opponent off-guard.
autocombo or 2M > 236H~8 > 214U > (delay)22U > 5H > 623L > 9U > (delay)j.2U (> land > j.6U whiff > j.M fuzzy)
The easiest midscreen fuzzy setup, but with downsides: it is either a fuzzy or a safejump, but never both at the same time. Hit the j.2U on the top seal early for fuzzy, late for safejump. Also, the rigidity of it leaves the least room to do tricky non-fuzzy things to your opponent.
autocombo or 2M > 236H~8 > 214U > 22U > f.L > 623L > 9U whiff > j.H fuzzy
The most popular midscreen fuzzy. The combo is easy, but getting the height for autotime j.H fuzzy can be difficult, so you may have to manual time the j.H, or eyeball it and go low if your j.H hits too high. If you press a quick j.3U you can go for a crossup low. You can also do j.6U2U with the top seals after the 9U whiff for a fast crossup. Loses to block button, but sometimes you gotta keep 'em honest.
autocombo or 2M > 236H~8 > 214U > (delay)22U > c.H > 623L > 9U > delay j.M (> j.7U6U whiff > j.H fuzzy)
The rare 7 input. Fairly difficult setup due to the awkward j.M link. Does a fair bit more damage than the previous combo and gives more corner carry, and if you don't drop you're guaranteed to have the height for autotime fuzzy.
autocombo or 2M > 236H~8 > 214U > (delay)22U > c.H > 623L > 9U > j.M (> 22[L] > j.6U whiff > j.M fuzzy)
Slightly difficult setup. Can crossup depending on your timings, which is funny but often results in you getting bravecountered straight into the corner. Weirdly if you crossup you seem to always get a standing hit on the opponent even if they crouch and get hit overhead by the first j.M. To avoid crossing up delay the 22[L] cancel slightly. Crossup is a safejump, sameside is not. Ability to mix up movement with other seal placements leaves a lot of room for devious trickery, e.g. press j.22L > j.3U instead for a quick low.
autocombo or 2M > 236H~8 > 214U > (delay)22U > c.H > 623L > 9U > 2U (> 9U whiff > j.H fuzzy)
Easy combo for a difficult setup - the timing on the fuzzy j.H is quite strict. Do both of the first two dashes with one U press for help lining it up. Delay the last 9U dash very slightly for fuzzy, or press it early for an empty jump low.
(starter) > 623L > 6U > 2M > 236H > 214H > (delay)623H > j.H > rejump j.H (> j.6U whiff > j.H fuzzy)
When you hit your starter but don't quite reach your seal for a gale dash extension, you can use the forward movement from light spin to convert into a full combo. If you think you'll reach the corner with 214H, this sets up for an easy fuzzy. Need to eyeball the delay on the 623H based on distance from corner; sending it as early as possible won't let you connect j.H after.
(starter) > 623L > 6U > 2M > 236H > 214U > 2H > 623H > 22H or 22L
If you don't think you'll reach the corner with 214H, you can do this instead to push your opponent Quite Close to the corner and set up seals.
(starter) > 623M > j.3U > (delay)214H > 5H > 623H > 22U
A similar concept with 623M. More damage than the 623L route and keeps your tornado cooldown, so if you're choosing between this combo and the 623L one, you'll generally prefer this one. If you know you won't reach corner with 214H, you can go straight into 214U from the j.3U for better corner carry.