OMG... i just watched that video... damn... at first glance XIII Clark seemed meh... but as time passes, i keep seeing more and more things that amazes me about him... XIII Clark seems to be a combo/juggle machine... imo he has great momentum... you can reset or KD the opponent after all your combos... a little better version of that combo would be...
j.C, ("cr.B, cr.A" or "S.D"), A Gatling Attack, Vulcan Punch (1hit), [DC] Ex Gatling Attack, C Gatling Attack, Vulcan Punch, A Gatling Attack, j.D...
you should be able to replace the second vulcan punch for an EX version and follow-up with SAB/UAB...