>>49580301
You have to have the magatama equipped when you level up for the corresponding resistance to raise. For example, if you level up with gehenna equipped your fire resistance will raise(up to a maximum of null). Shiranui will also raise fire resistance but since it's a lower tier it can't raise it above 50% resist. It's 5% per level up to whatever the cap of the magatama is. This is the naked resistance of the demifiend before taking into account whatever resistances the magatama itself gives passively.