Elemental Protection Skills
Most of how a Yo-Kai will sustain damage is how strong it is against a certain type of element. For example, a Yo-Kai like BLAZION will be highly immune to fire type attacks but considerably weaker to water attacks. Some Yo-Kai are masters of the elements and use their elemental powers to guard themselves from damage or hit with an even stronger elemental force.
All of the resistances protect the same percentage (70%), just in a different element.
Castelius II‘s unique plating allows him to withstand fire and ice.
Dromp‘s earth like body allows him to take most of the Lightning damage he takes without harm.
Castelius Max’s powerful coating grants him strength against Water, Ice, and Wind.
Castelius III is safe against Earth and Wind elements from really harming him.
In that vain, there are some Yo-Kai who posess great strengths in their home element, and because of that, their elemental attacks get a boost of 1.2x.
Snotsolong gains a boost to his water attacks, probably because he used to be a duck.