First off, just take into consideration what I'm saying instead of "Well if you're using the Charge you're doing it wrong" or "You'll rarely use Cutter so why bother" or something else like that.
Cutter-line Charge attacks are just, inadequate compared to other sword Charges, absolutely no reason to use them at all because, it doesn't give good adequate knockback and keeps you stationery.
So, my suggestion (Remember, take this into consideration) for a new Charge that's hopefully adequate and not overpowered is, instead of normal slashes:
The knight, once unleashing Cutter charge, would take a step back (About as much as some gun's step backs) then, the arm in which the Cutter is held would perform stabbing motions at the enemy, which would create phantasmal swords looking as if they're stabbing and jabbing the enemy in front of the user (Like a barrage/flurry of swords), however it wouldn't be directly in front of the Knight, it would have about as much range as a Heavy Swords second slash, and it would keep you stationery like the old charge, but, in addition to the range, the flurry of swords would have some knockback, adequate enough to keep the Knight protected IF they use the Charge at the right time and in the right spot, so like if enemies can get around your barrage of swords, and you're still using the Charge, you're probably gonna get hit.
Oh, and the only thing about this that would change when using a Hunting Blades Charge would be that the swords turn into phantasmal Wolvers that leap forward and bite the enemy.
Seriously, take this into consideration, the current Cutter charge is just normal slashes that keep you in the same spot and make you incredibly vulnerable.
I agree with this completely, and that actually sounds like a pretty reasonable thing to do.