
AngryOrc |

So my dream is to play a giant barbarian and look down on those puny creatures that appose me. When I saw Demonic Bulk I was like yeah this is the stuff but now our dm added a Mythic level to us. So this made me wonder can I be a bigger giant? Would Augmented Spell Enlarge Person work on Demonic Bulk(Su)?
bloodrage, you can choose to grow one size category
larger than your base size (as enlarge person, even if you
aren’t humanoid).
You can increase the target's size by up to two size categories, to a maximum of Huge. If the target grows two sizes, its weight increases by a factor of 25, it gains a +4 size bonus to Strength, and takes a –4 size penalty to Dexterity and a –2 penalty on attack rolls and to AC because of its increased size. A Medium humanoid creature whose size increases to Huge has a space of 15 feet and a natural reach of 10 feet. Mythic enlarge person counters and dispels mythic reduce person.

ecw1701 |

Well, I'm the DM...and I'd say they do *not*.
Since the spell costs a point of mythic power, AND a mythic spell slot, it can't be approximated by a basic class feature.
Learning Mythic Spells: To learn a mythic spell, you must either select the Mythic Spellcasting universal path ability or the Mythic Spell Lore feat. In doing so, you unlock the secret of using your mythic power to amplify non-mythic spells you choose.
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. Unless otherwise specified, casting the mythic version of a spell doesn't take any longer than casting the non-mythic version.

Movin |
Short answer. No, not as a part of your rage function at least.
Long answer
Supernatural abilities are not considered spells due to them having the Supernatural type rather than the Sp of spell-like.
Demonic bulk is not Enlarge person in the same way that Wild shape is not Beast shape for mythic abilities. Sadly.
Because you are gaining the effects of the spell but are not in fact casting the spell itself, you end up not being able to utilize the mythic version of the spell.
Good news though, Dispel magic does not work on Supernatural abilities, and cannot be counter spelled. so where a counter happy arcanist bad guy could stop you from casting mythic enlarge person he cant put the breaks on your Demon bulk unless he happens to drop an anti-magic field.
There is nothing preventing you from taking mythic spell casting and casting the mythic enlarge person spell from your blood rager spell selection though. It would take the normal casting time and make you huge. Then you could rage and get claws.