[Ability] Beyond Mortal Seeming
Prerequisite: One Fantastic Mythos

Choose one of Dexterity or Intelligence. This Excellency may be purchased once for each Ability Score, granting a +2 enhancement bonus to the chosen ability.

Once you have at least one Legendary Mythos known, this Excellency may be purchased a second time for each Ability Score. This second purchase increases the enhancement bonus by 4, to a total of +6. 

Blood-Ebbing Prana
Prerequisite: -

Through subtle, possibly unconscious, control over the ebb and flow of your blood, you are especially difficult to exsanguinate. You automatically stabilize when reduced below 0 hit points. At the beginning of your turn, you may either recover from one point of Constitution damage or reduce ongoing bleeding damage that you are suffered from (such as that inflicted by a Bearded Devil's 'Infernal Wound') by 2 per round.

At 6th level, you may recover from Consitution Drain as if it were Constituion Damage during natural rest and recovery.

At 10th level, you may treat Constitution Drain as Constitution Damage for the purposes of all recovery, including that provided by this Excellency.

Breath of Meaning
Prerequisite: -

You come to learn the ancient and elemental languages of the Prime Material Plane, their meaning drawn into you with a breath from the world, and your breath returning it in kind. Add Auran, Aquan, Terran, Ignan, and Draconic to your list of languages known. If you already knew one or more of these languages, replace them with new ones.

At 6th level, you can understand all spoken language, and may learn new languages extremely rapidly, picking up a conversational vocabulary just by conversing with a native speaker for a few minutes, and mastering it simply by spending a few days living among native speakers. This does not aid you with reading or writing these languages. In addition, you gain a +10 competence bonus on Spellcraft checks to identify a spell being cast if it has a verbal component. 

Elemental Primogenitor Blood
Prerequisite: One Fantastic Mythos

So infused with elemental power has your body become, that it has been altered down to its procreative processes. Your children, when birthed, will never suffer from genetic defects or hereditary illnesses from either parent, nor will they ever be stillborn or born unviable for whatever reason, such as prematurity, and their birth will not harm their mother. While pregnant with a child, you suffer no debilitations great enough to impede you, even in strenuous activities, such as combat, nor do such activities harm the child, and the growing proto-infant is immune to poisons and diseases that might pass from you to it.

Further, you breed as if you were a unique Elemental. For example, a Human Kathodos with this Excellency that mates with another Human would produce a Half-Elemental Human, whose children would, in turn, be Genasi. If that Human Kathodos mated with an Archomental, the resulting child would be a new, fully unique, fully Elemental creature. If they mated with a Bronze Dragon, the child would a Half-Elemental Bronze Wyrmling.

Which element your child inherits is determined randomly, with a higher propensity towards a particular element if you favor one above the others. If you do not qualify for an [Internal] element, your children will not be born of that element.

Flowers-And-Roots Extrapolation
Prerequisite: 4 ranks in Knowledge (Nature) and Knowledge (Geography)

When you make a Heal or Handle Animal check, you may instead make a Knowledge (Nature) check and substitute the result. When you make a Survival, Gather Information, or Knowledge (Local) check, you may instead make a Knowledge (Geography) check and substitute the result.

Sea-of-Chi Understanding
Prerequisite: -

Using your own body heat as a source of ignition, you can create a spark to ignite the air around you, and thereby use [External] Fire Mythos as if they were [Internal]. Furthermore, by stoking your inner flame, you can stave off the cold. You gain Cold Resistance equal to your class level and a +2 bonus on saving throws against spells with the [Cold] descriptor or other effects that rely primarily on cold.

Skin Like Adamant
Prerequisites: -

You have hardened over your years of training, awakening the earth within your bones.

You gain Toughness and Improved Toughness as bonus feats.

At 6th level, you gain your Constitution modifier as an untyped bonus to your AC against all critical confirmation rolls; if you also know Universal Muscle-Hardening Exercise, the bonus is instead equal to the higher of your Dexterity and Constitution modifiers.

Courtesy of Amechra

Universal Muscle-Hardening Exercise
Prerequisite: -

Although nature may have not gifted you with an abundance of innate toughness, you have been hardened in the crucible of life and what natural talents you do have can make up for other physical shortcomings. You may substitute your Dexterity in place of your Constitution for the purposes of calculating your Fortitude saving throw, as well as for how long you can hold your breath, and on checks to continue running, or avoid nonlethal damage from forced marches, starvation/thirst, harsh climates, and swimming.

Wind-Fire Sky Stride
[Internal][Air or Fire]
Prerequisite: 10 ranks in Jump

With a thought, you may project sustained blasts of air or fire from your limbs, allowing you to propel yourself through the air. You gain a Fly speed equal to your land speed with Good maneuverability. If you have 13 ranks in Jump, your maneuverability improves to Perfect.