How do Mythic Spells known interact with classes that can retrain spells known?

Question

"To select a mythic spell, you must be able to cast the non-mythic version or have it on your list of spells known." If you don't know it and you can't cast it, then you can't select that spell. Seems straightforward enough.

Most of the classes that can retrain spells known do so slowly and their interaction with Mythic Spells seemed obvious. Until the Advanced Class Guide was released. The Shaman at 6th level or higher can use the Wandering Hex class feature to select Arcane Enlightenment from the Lore spirit, choosing a handful of spells from the sorcerer/wizard list to prepare that day. The next day, they're gone, and the shaman can choose the hex again and select a new loadout.

Issues of "balance" aside, do your Mythic Spell picks get refunded if they're no longer valid choices? If so, do you have to choose them again immediately, or can you wait until you've used a class feature to choose new spells you couldn't normally pick? If not, are they retrainable for a small commitment of gold and time? Or do those Mythic spells just stay there until you pick those spells again and get them back?

Rules-as-written is strongly preferred, as I like to come from a strong understanding of the rules prior to making a GM call to change things or deny a proposed change, but statements of developer intent (even if unofficial) or comparisons to how RAW handles similar situations are also very helpful.

Answer 1

First, I'd like to say that this kind of oversight and poor editing is common in the Mythic rules, and it's likely that whoever wrote the Mythic Spellcasting rules wasn't thinking about retraining spells when they wrote the feat and power. Thus, any ruling you make on this will likely be supported by at least one interpretation of the rules text.

That said, I would say that the rules as written most support the interpretation of the selected Mythic spells remaining static once chosen. In the description of the feat/power, there is no mention of changing the Mythic spells selected, and generally choices made in feats cannot be changed without specific retraining. This implies that the selection process is something that happens once, when you take the feat, and is static afterwards. Since nothing says that you can rechoose your Mythic spells if you stop being able to cast the regular version, you can't. Those Mythic spell choices become basically inert until you regain the ability to cast those spells, or use some kind of feat retraining to get a different set of Mythic spells.

Answer 2

http://www.d20pfsrd.com/mythic/mythic-magic:

Mythic spells draw upon the caster's mythic power to create more powerful magical effects-mythic fireball sets affected creatures on fire, mythic mage armor can negate critical hits, and so on. These spells aren't separate spells you gain as a spell known from your spellcasting class, but rather mythically charged versions of spells you already know.

From the above it's pretty obvious: Technically, there is no separate mythic version of a spell a character could prepare and cast, even if he could not cast the nonmythic version. In order to cast a Mythic spell, you need to

A. cast the nonmythic version of that spell

and

B. spend one (or more for augmented versions) uses of mythic power.

Thus, if you are - for whatever reason - unable to cast the nonmythic version of a spell, you are also unable to cast the mythic version and in so far your "mythic spellcasting"-ability/feat ist wasted. That should be considered before choosing mythic spells.

Answer 3

http://www.d20pfsrd.com/mythic/mythic-feats/mythic-spell-lore-mythic

To select a mythic spell, you must be able to cast the non-mythic version or have it on your list of spells known.

http://www.d20pfsrd.com/classes/hybrid-classes/shaman/spirits/lore

Arcane Enlightenment (Su): The shaman's native intelligence grants her the ability to tap into arcane lore. The shaman can add a number of spells from the sorcerer/wizard spell list equal to her Charisma modifier (minimum 1) to the list of shaman spells she can prepare.

RAW seem to state that, should a Mythic Shaman take the Mythic Spell Lore feat while temporarily bonded to a Lore Spirit, that Shaman could choose to gain the Mythic versions of any Sorc/Wiz spells granted by the Lore Spirit.

I see nothing to indicate that they would lose access to the Mythic version of a spell should they lose access to the non-mythic version.

http://www.d20pfsrd.com/mythic/mythic-magic

Casting Mythic Spells: If you know the mythic version of a spell, any time you cast the spell, you may expend one use of mythic power to convert the spell into its mythic version as you cast it. This doesn't change the level of the spell slot you use to cast the spell. If you're a caster who prepares spells (such as a cleric or wizard), you never have to prepare the mythic version of a spell-if you prepare the non-mythic version, you may cast it as the mythic version by expending one use of mythic power.

(emphasis mine)

This, however, suggests that a Wizard could prepare the Mythic version and not the non-Mythic version. Casting the Mythic version of a spell requires expending a Mythic point. Thus, RAW seems to indicate that the Shaman who used a Lore Spirit to gain access to a Mythic spell would retain access only to the Mythic version if they lose access to the non-Mythic version.

Example

Seamus the Shaman bonds with an Arcane Spirit, and uses that bond to learn Cloudkill. While bonded, Seamus takes the Mythic Spell Lore feat and selects Cloudkill as one of the spells for that feat. Later that day, Seamus comes across a swarm of ants; being the only party member with any AoE attacks, Seamus uses Cloudkill to destroy them with extreme prejudice.

The next day, Seamus chooses to bond with a Battle Spirit. He loses access to Cloudkill, but retain access to Mythic Cloudkill. His party again comes up to a swarm of ants, and he is still the only character with an AoE attack. He reluctantly casts Mythic Cloudkill, thus not just destroying the ant swarm, but also making the ants who stayed home quake with fear for no adequately explained reason.