When Lina uses spell, fiery soul get 1 stack, when Lina continue to stack fiery soul and reaches 3 stacks, buff remaining time continues the animation until the end. When lina exceeds third stack(max of 3 stacks are not exceeded) the refresh of third stack is not shown on remaining time animation, player do not see how long remains to end of fiery soul. Fiery soul buff remaining time is dark green(like all time of buff expired) until it expires, then buff disappears.