Benefit: You can learn a number of mythic spells equal to your tier and can expend mythic power when casting them to enhance the results. To select a mythic spell, you must be able to cast the non-mythic version or have it on your list of spells known. Every time you gain a new tier, you can select an additional mythic spell.
This bard also has has the metamagic feat Empower Spell
Benefit: All variable, numeric effects of an empowered spell are increased by half including bonuses to those dice rolls. Saving throws and opposed rolls are not affected, nor are spells without random variables.
May he use the feat Empower Spell, on his Mythic Cure Critical Wounds ?
The damage cured increases to 8d8 points of damage + 2 points per caster level (maximum +40). The spell cures up to 4 points of ability damage if the target is a living creature. The target chooses what types of ability damage are cured.
If he can, how would you calculate the damage healed ?
What led me to this questions is the page on Mythic feats, especially this part :
Mythic and Metamagic Feats
You’ll notice there are no mythic metamagic feats. Because mythic versions of spells are, in a way, metamagic of their own, and there are many mythic abilities that empower such spellcasting, there is no need for mythic metamagic feats. If you desire more potent spellcasting power, select the Mythic Spell Lore feat multiple times.
If I follow this line of thoughts, would that mean that adding metamagic to a Mythic spell, be like adding metamagic to a spell with another metamagic effect ?