Pride or Unit

A popup gives you a warning that you cannot change your choice on this character.
Unfortunately, there's nothing telling you what the choice actually means in the game.

The choice only affects characters in the Kyrian covenant

I chose Phalynx on one character and Larion on another. Both characters can now have Gatamatos and Lentios as guardians simultaneously, however:

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• Gatamatos is limited to the Forgefire Outpost, Namea's Retreat, The Golden Pasture & Greatwing Roost areas, but has no time limit
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• Lentios requires Larion Treats and can be taken all over Bastion, but only lasts for 10 minutes
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This choice has absolutely nothing to do with mounts. If you want any of the Kyrian specific mounts you just need to be in the Kyrian covenant and progress accordingly

NOTE FOR KYRIAN COVENANT CHARACTERS:
If you chose Phalynx you will have Pelodis as an companion. If you side with Larion you will have Nemea as a companion. Both attack the furthest enemy and you cannot have both on the same character. The only difference I can see is that Pelodis does Holy damage and Nemea does Physical damage. I cannot say which one has a clear upside over the other since ideal damage type is dependent on the adventures available

So many quests just to have to make an irreversible decision in the end while you don't even know what the pros and cons are or what it is even good for...

I searched for details on this, could not find any helpful information and ended logging out because I did not want to make a decision I regret later.

This is NOT what I call fun.