At 09 sec just have a look on your meter bar. The lightning kick MB is garanteed only on hit, so it costs 1cm of meter + trait.
I'm doing 3 LK, b2, 2, LK, b2, 2, f3, charge after a sonic pound MB and also online. If I start combo with the LK (better juggle for executions), i'll do zyphox's original combo : trait, LK x4, b2, LK, b2, 2, f3, charge. 61% from b2, 2.