With sand kicked up with the left leg of the opponent, Lancer was able to deduce various situations simply by taking in account this information. Yes, Lancer was blinded, but his memory bank was as vivid as ever. Left leg was used for the kick of sand, of course he would remain on his right foot at that moment during the kick. Lancer kept calm, he didn't need to worry, a tactic such as this he has confronted before, and his training allowed for him to simply react as he should have. Lancer would use his left foot, picking it up ever so slightly, and jabbing his left foot, specifically the sole of his foot, onto the ankle of your right foot. This is done right after the sand kick, so you wouldn't have enough time to move downward as you wanted, despite Lancer not knowing that, it would happen in succession after the kick. The jab kick was more forward, then it was downward, this way, the sand wouldn't create a cushion for the attack, so the full force of the attack would hit the bone. The aim of the quick jab kick was two things: to bruise the ankle, forcefully making stability on that foot much more difficult. Second, would be, obviously, balance distortion. Your bodily reaction would depend on how you allow it however, Lancer knows either the opponent will allow the ankle/foot to be pushed back and attempt a straight torso, but this would make his center of balance terribly destroyed, and slowed down, essentially standing on one foot. Second theory would be the opponent would have the momentum of the kick to just go backward with his entire body, hurting his balance, but he can still be agile enough to move. If he tried to fight the jab attack, serious bruising would be the outcome.
Lancer decided to use a quick attack no matter the situation, after delivering the jab kick, he uses the same foot, and rises it higher this time, aiming to straight kick your chest, bouncing slightly forward to make sure full contact, and pushing momentum is accomplished. This would knock the air out of you, and further push you, likely collapsing on the ground. Lancer keeps his body standing sideways on the opponent, even as the kick happens, he would slightly lean his body back during the kick to gain full extension.