Pretty sure the highest CHASE is 16 in our version. There is the starting attack, jutsu or otherwise, 1 Main can perform 3 chase, 2 from summon and 1 from talent, 1+3=4 Chiyo 10 puppet can perform 6 chases, 4+6=10 There are quite a few character that can perform 3 chases, 10+3*2=16
I don't think there are any ninja other than Chiyo with more than 3 chases, and that makes this the max.
As for the combo hit thing that is chased by "high combo", that thing can go into the hundreds.