Charming Soul (Human Favoured Soul with Persausian feat)

A variant human that chooses the Persausian Feat, not only can get an 18 in Charisma at level one using stat array, but can charm anyone in a none combat situation in a none magically way in a minute, and if they already, are skilled in the skill, they get expertise in it.

So add that to a Favoured Soul with the guidiance cantrip and that is a powerful combo. +4 charisma mod to you spells, both to hit, DC, and to healing with cure wounds, and to Charisma skills.

I'm unsure how you could achieve an 18 in Charisma at character creation. The Variant Human allows a +1 to two different stats, so the highest that you could raise Charisma to would be 16. The UA Diplomat Feat allows for an additional +1, which takes your Charisma stat up to 17; which achieves a +3 modifier, not a +4.

If I have overlooked something, I am happy to be corrected.