The spells are what lvl sub whm you have. now that i have a whm thats lvl 12 subbed it does healing breath II sometimes. An the weirdest thing i found out is that......I got poisoned used my weapon skill and then my Wyvern used some kinda breath attack to heal my poison, and it worked. Once i have a lvl 21 whm sub my Wyvern will b able to do Healing Breath III randomly if i have the spell. So to sum it up Wyvern can debuff and use healing breath with anykind of subed mage including DRK or PLD. The bad thing is, its completely random on when he will do it. so its not all that good. and without a melee subbed like WAR or THF your Wyvern will NOT use a breath attack that does damage.