Question: Regarding Doule skills and reset

[御萧xXLJXx]

How does the double skills work? when you buy it, if you buy a rest skill using vouchers, does that reset both set? or you have to buy it separately for both set of skills?

[ProNab]

How does the double skills work? when you buy it, if you buy a rest skill using vouchers, does that reset both set? or you have to buy it separately for both set of skills?

You pick which to reset, you reset only 1