each skill has its own cooldown, but it should not affect the other two skills. at most, the other two skills (regardless of what they are) should have a standard of 30 sec to cooldown, while the ability used cools down at its normal rate.
E.g. [skiil 1]:CD 17 sec, [skill 2]:CD 42 sec, [skill 3]:CD 57 sec
if skill 2 is used, then skills 1 & 3 cooldown for 30 sec, skill 2 cools for 42 sec at its normal rate.
i suggest this because it seems odd that one cooldown would be used for all skills when really, thats a waste of time.
"it seems odd that one cooldown would be used for all skills when really, thats a waste of time."
The cooldown affects all skills so that players won't release every skill at once. It'd be too OP.