Air grabs is literally a specific character niche that only a few characters have, they are EXTREMELY GOOD (especially in Brawl). Like, very very very very good. If every character had one, the game would be crazy scary and potentially obnoxious, but could still be really cool in a floaty-ish game like Brawl.
However, in terms of what's available/execution, characters with good/solid frame traps (especially aerials) already have the feint ability to fast fall into grab faster than reaction (Marth, Wario, lots of bairs), and becomes one of those 50/50's that exist in Brawl with very solid buffering (and what ended up proliferating roll away strategies, MK rolling in a lot [], and spot dodgers to spot dodge), it's still strong due to how important power shielding is in the game for achieving punishes. Triangle jumping and the general frame advantage of L cancelling in Melee has similar impact.
Wario, Kirby, Lucario, Dedede, Bowser, Ganondorf.
Bowser's Koopa Klaw (sp?) is legitimately one of the best moves in the game, but happens to be on a really ass character without any other solid option (even if that one option is super solid, characters need more for viability).
Wario's bite leads into combos, is fast, low cooldown, beat's spot dodges, has grab armor. It's better than Bowser's.
Lucario has a weird one, pretty sure you can't grab out of the air (it's just a projectile in the air I'm pretty sure). However it has the unique ability to immediately have your grab come out if you land on the ground immediately after starting side-b. It's so hard to use, but a potentially 1 frame grab from the air? @
Trela wrecked me with this for weeks (it never stopped
), it's so awesome.
Kirby/Dedede/Ganondorf all soso, especially ganondorf. However they have their uses, primarily beating shields. Dedede's is solid enough to use the move in the Ice Climbers match up, and @
Vex Kasrani makes that match up look close to even with having such a solid landing option that beats shields/grab/dash dancing (3 of IC's four best options). I could be wrong/not up to date with anything super recent, but Vex has beaten every ICs he's fought this year I think.
In other words,
maybe good if everyone had one (kinda like kill throws in smash 64)
But mother of god.
Probably not a good idea. Trust me.
If you're concerned with some multi directional air to air combat stuff, they're called aerials and can be executed by tilting the C-stick in all 4 directions while in the air, the general free movement (vertical/horizontal) allow you to do all that you would want. If it didn't beat shields it would be superfluous, and there are no "shields" in the air so it could either beat air dodges (why?) or you should just be more on point with your aerial execution and spacing.