Once he got the initial feeling down, Ackster realized what he had to do and feel to learn how to activate Last Stand.
The feeling of using Limit Breaker that had pointed him in the right direction had been the feeling of releasing the shackles around his body, easing up his limits, and allowing him more freedom.
As far as Ackster could tell, Last Stand should almost be the same, just a little different. It wouldn't be as delicate or precise as Limit Breaker.
That meant Ackster had to take the smooth energy enveloping his body and releasing his inhibitions that was Limit Breaker and make it more violent.
Fortunately, the desire to break his limits and ease the shackles symbolizing those limits had been enough to let Ackster nudge Limit Breaker to activate.