These Hybrid Spirits will only be castable by Lv99 SMN with the prerequisite of um, something which I have no clue of yet. None of the spirits will have a Favor linked to them, similar to current spirits. They will also have a perpetuation cost comparable to Celestial Avatars. The time required to cast a Hybrid Spirit will be equal to Avatars and not Spirits.
The Hybrid Spirits would behave similarly to the current Elemental Spirits, when engaged, they will cast offensive spells when they have been assaulted on a target or auto-assaulted due to aggro. The spells would be based on their element type and the tiers would scale up to V and they will also cast area of effect spells (-aja). Differing from typical Spirits, when passive, these will cast Enhancing Black and White Magic spells on themselves. Another distinguishing feature compared to typical Spirits, these hybrids will use Blood Pacts based on the actual hybrids' abilities. Hybrid Spirits will not have any Ward based Blood Pacts. Under the effect of Astral Flow, they will not gain additional Blood Pacts.
Elemental Siphon may be used while these spirits have been summoned. The amount of MP recovered will depend on both the weather and day just like current spirits, with the added benefit and disadvantage of having dual elemental properties. For example, on Darksday and double Sandstorm weather, the Brygen Spirit will benefit most from using Elemental Siphon compared to either Dark Spirit or Earth Spirit. Because of these elemental properties, Baelfyr and Ungeweder will both suffer penalties from using Elemeltal Siphon during said Day and Weather conditions, if using Gefryst, there will be no benefits nor penalties received for using Elemental Siphon under the aforementioned conditions.
Light/Fire
When passive this spirit will work similarly to the current Light Spirit, due to it's tendency to cast spells randomly such as Cure VI, Protect V and Shell V, Curaga V, Haste II, and MAYBE even Regen V (Although I suppose Regen II should suffice). Those enhancing spells will have priority over the following spells:
The following offensive spells will be cast at random when assaulted on an enemy target:
Burn, Addle, Fire V, Firaga III, Firaja, Flare II
The two following Blood Pact: Rage will be exclusive to the Baelfyr Spirit only:
Blinding Fulgor - 15' Area Light damage centered on Spirit. Additional effect: Flash
Searing Tempest - 15' Area Fire damage centered on Spirit. Additional effect: 25 HP Burn
Dark/Earth
When passive this spirit will cast the following enhancing spells on itself:
The following offensive spells will be cast at random when assaulted on an enemy target:
Rasp, Slow II, Break/Petrify, Stone V, Stonega III, Stoneja, Quake II
The two following Blood Pact: Rage will be exclusive to the Byrgen Spirit only:
Tenebral Crush - 15' Area Dark damage centered on Spirit. Additional effect: Knockback
Entomb - 15' Area Earth damage centered on Spirit. Additional effect: Petrify
Water/Ice
When passive this spirit will cast the following enhancing spells on itself:
The following offensive spells will be cast at random when assaulted on an enemy target:
Frost, Paralyze II, Blizzard V, Blizzaga III, Blizzaja, Freeze II
The two following Blood Pact: Rage will be exclusive to the Gefyrst Spirit only:
Spectral Floe - 15' Area Water damage centered on Spirit. Additional effect: Terror
Scouring Spate - 15' Area Ice damage centered on Spirit. Additional effect: Paralyze
Wind/Thunder
When passive this spirit will cast the following enhancing spells on itself:
The following offensive spells will be cast at random when assaulted on an enemy target:
Shock, Stun, Thunder V, Thundaga III, Thundaja, Burst II
The two following Blood Pact: Rage will be exclusive to the Ungeweder Spirit only:
Silent Storm - 15' Area Wind damage centered on Spirit. Additional effect: Gravity and Silence
Anvil Lightning - 15' Area Thunder damage centered on Spirit. Additional effect: Stun
The names of the the aforementioned abilities and the additional effects are based on observations from playing with Escalents in Yorcia Skirmish II. The enemy Hybrid Elementals in game use their special ability attacks when enough TP has been accumulated, the Hybrid Spirits will however be able to use the abilities through the use of Blood Pact Rage. The amount of damage dealt would be modified by TP and by the Summoner's equipment, for example Pet: MAB+, Blood Pact Damage+, and Avatar: TP Bonus. On the contrary, the duration of the additional effects will be based on Summoning Skill and Pet: Magic Accuracy+ on the Summoner's Equipment.
As previously mentioned, all spells would be cast randomly by the Spirit, summoning skill affect "the spirit's AI and will shorten time between spells casts" just like current spirits. All Blood Pacts will have the same MP cost of... 250? MP, except when under the effect of Apogee. All Blood Pacts will (not?) have skill chain properties.
Although this is only a completely hypothetical implementation, I'd like to know what you guys think. If you have any other reasonable ideas or suggestions, let me know and I might just add them onto the post.