Each character learns their own skills (not sure if they all learn new skills at the same level or if it varies by character.)
Here’s my current skills for the main character at level 16:
Magic comes in the form of various Crystals:
Anyone can attach any crystal and then use that magic “skill.” It looks like there are two limits on how many magic skills you can set… every 20 levels you get a new slot (until level 60) and then you can unlock two additional slots for 100P each. (This is probably where I’ll spend my IAP.)
In battle, magic and skills both cost energy or “EN” – however you typically earn far more energy from the battle results, than what it costs to use your skills.
(Also, the Auto-Restore button when you’re in dungeons uses energy to heal everyone in your party, and I’m able to use this feature after EVERY random encounter with no worries about running out of energy…)