Some online friendly labby combos for me are: 5a>5b>2ab>214a> (if meter) 236236 C or D. (very lienent on the execution time for the super, so its good for online when dealing with lag).
5aa>5a>2b>j.b>j.c>214b (can also be followed up with beast super, but IMO hard when dealing with the slightest bit of lag due to how tight the timing is).
5a>5b>236a>6>a>66>5aaa>214a>236236 C or D. (again very lienent on the super timing, and deals about 3.9k damage with just the c version of the super. can be done off a simple hit confirm of A with red OR yellow axe.
I know that when you do not have red or yellow axe that chain knuckle will not combo but keep in mind its good for mind games. Its basically a 50/50 chance. both attacks come out very fast and one is a medium, and the other a low, so its more or less a guessing game for the opponent if you can keep the pressure on IMO. Its also risky IIRC because i dont believe either attack is safe? I may be wrong on that though. Just like off the A hit, i believe you can combo off the low B, by following up with 214 A but I may be wrong about this also. So IMO its a high risk high reward mixup. Kinda reminds me of Kazuya froom SFxT. He plays quite similar in the high risk high reward department of his 50/50p mixups.