Okay, a lot of his strings seem to link into gravity mine which is a great way of applying pressure. Worked out a 38% two-part combo (no meter), but it's not 100% reliable (see below):
112, gravity mine, dash (don't dash too early or you'll throw a far mine). 8% before the mine.
Opponent is forced to block low, and it seems you can catch them with the orbital laser if they do. If they don't and get caught by the mine, you can:
B3, JI3, D3 for another 30% (including the mine). After the B3 bounce you can also Gravity Blast but that'll do 25%. Of course, you can MB it and (in theory) get a higher combo off it.
So 8% setup with potential 30% on top. Going to work on the following:
1) a fast overhead combo to follow up the mine in case it gets blocked.
2) variations by moving the mine location and trying to push the opponent back into it (or punish roll-away with the mine and use SPACE LASERS to deal with crouch-blockers).
disclaimer: probably the first time ever I've tried figuring out combos from scratch so apologies if they're terrible
edit: add 2% by using Sky Fall rather than 112.