I have noticed that some skills consume a lot more SP than what is indicated beside the skills. At first I thought that it was normal since usually those skills hit more than once to complete. However, after having only the minimum requirement to use the skill, I can still produce the same amount of hits, or combos that would consume a lot.
For example, I have used the Ice Spear Dance III which has a total of 3 combos to complete. It needed 42 SP to use, so after using it, I consumed 3 times the normal SP amount it requires. However, after only having 42-50 SP left, I used the skill again, and it still completed the combo, this time without using more than 42 SP.
My question is, is it intentional? Or is it a bug that needs to be fixed? That's all.