found an interesting bug with the skill resets.
if you managed to enter fairy springs where the npc is able to only reset one category of skillset instead of the entire thing: do the following:
1. get passive upgrades 1, 2 and 3 of any sort (in my case, magic attack up 1, 2 and 3)
2. go to magic page, and make sure you got the 3 passives up.
3. reset the sword skill tree (using Rein in my case).
4. upgrade the 3 first, then upgrade 1. the 2 will bug out.
more interestingly, doing this gets you 150 magic attack with this instead of only 120 attack.
edit: here's a much easier step:
1. use reset hammer
2. (in Rein's case at least): go to magic skill tree and level up the non elemental spell. uncluding the matk upgrades 1,2,3.
3. reset the sword skill tree.
4. go back to magic page, upgrade tier 3 first, then 1. the 2 will bug out.