The skill that Ronald used was called Wraith Phase. It was similar to Jack's Shooting Dash. It was a movement skill. The difference was Ronald's Wraith Phase could pass through obstacles. But it had a shorter range compared to Shooting Dash, only covering six meters distance even at max level.
Wraith Phase gave its user the ability to move three times, the same as Shooting Dash. But when the Shooting Dash user only had the time to deliver one fast attack in between the dashes, Wraith Phase gave its user a time gap of ten seconds maximum before the user changed into a shadow and moved again.
This ten-second gap gave Ronald more tactical advantages, as he could shoot at his opponents after dodging using Wraith Phase. When his opponents came again before the ten seconds expired, he could again turn into a shadow and moved away. This made him appear as if he was executing the same movement skill three times in succession with seemingly no cooldown time.