VERY early impressions.. but I think Manta is going to be a rough MU.
He can contest any kind of leap attempts it seems.. From close, his d2 whacks you out of the air very easily, and with his extremely solid dashes and walk speed, he can often just panic dash to safety or literally walk away from any real danger. From mid to far ranges it seems he can j3 to cover the entire screen in front of him and smack you out of the air. You can to cancel out of course, and bait the j3, but even then, he can forgo j3 entirely and air shark attack you pretty effectively.
Manta of course has some of the best anti-zoning around, so we cant rely well on gunshots. He can just duck about two of them and he's in, or tele on a read, or jump and air harpoon, etc. Of course we can read that and air gunshot, but if you're wrong, you only get one attempt and he's in. You can def catch him with a stray shot occasionally, but the risk/reward seems to be thoroughly in his favor and you wont keep him out for any length of time.
Neutral feels tough too. He has tons of options to stop f23, or just flat out contest it with his own f21.. but he can play back at a mid range where our f23 whiffs, he can still react to leap attempts and he can whiff punish the hell out of us with f21.
On knockdown, laser can stop shoulder it SEEMS. I had several get stuffed right out. Manta is generally extremely strong on oki anyway.
Dont get me wrong, these are SUPER early impressions, but Ive played the Beetle v Manta MU vs the same person and I felt WAY more comfortable. As Hellboy I felt like I couldnt do *anything* from *anywhere* without it being easily stopped, or adapted to. Obviously I need to run the MU way more, and IM not putting numbers on this, just passing along some observations. There may be some key to this MU that I totally missed, but when playing vs the same player as Beetle, I felt like I was losing to the player, but when playing vbs the same guy as Hellboy, I felt like i was losing to the character before I even got a chance to play the player, lol.