I beg to differ, by giving the favored soul the whole list, you are giving it 95% of domains possible. If we had a limited -emphasis on limited 'cause books have limited space- set of domains, we have artificially limited the amount and variety of concepts we can cover with the same subclass. If you want more, you are at the mercy of DM fiat. Besides it not only covers champions of the gods, but descendants of the gods and celestials.
That's all true and I understand your point. But by using a domain format you also open up the possibility of allowing non-cleric spells into the mix, such as Druid only spells for the fey or spells that are Wizard only that say Azuth or Oghma bestowed. Those other restrictions already exist, admittedly. Clerics don't cover every possible outlook with their domains. Druids don't cover all the land types with their circles. But you can certainly get thematically close.
I also just don't see that certain deities would allow their Favored Soul access to every spell. Kelemvor, for example, would never allow his followers access to Animate Dead (Yes I know every Cleric has access to it). Domains help steer that.
Edited: After seeing your post in the FS poll thread, I want to clarify. I liked the first FS attempt that gave the domain spells as known. Not as additional options to learn. This is all under the assumption that you are given those domain spells. If you aren't given the domain spells, then yes, the entire Cleric list is preferred.
That ship has sailed, bonus domain spells are a thing of the past. Having them would invalidate the subclasses in core, and designers long ago decided those were set in stone.
And well, favored souls are "special" in that they don't directly get their spells from a deity. They aren't dependent on the gods. While a cleric gets spells directly from their god, a favored soul derives them all from their divine spark, that can be imbued into them by a deity, but could as well be innate by virtue of their divine parentage.
That is an excellent point, in some ways the Favoured Souls are closer to the Chosen like Elminister or Manshoon (who is still a Chosen of Mystria, even though he gives her the finger at every opportunity) then clerics. Favoured Souls are basically part God (and in 5e fluff so are the Angels that spawned them), admittedly a tiny piece.
The Gods allow Clerics allow to draw power from them, they encourage Paladin's to swear oaths that link them to the ideals that Gods embody, but the Favoured Soul has their own divine spark, they are effectly proxies of a God, either by blood or by adoption, endowed directly with a piece of the God in their own souls. Obviously the divine spark isn't big enough to make them actual Gods, it's would be more of a spark of a spark, but it's does give them powers.
Look at how Eliminister and the other Chosen in the Forgotten Realms use their magic, innately, sorceror like, in some cases including healing.
Now Favoured Souls would be a particular breed of Chosen, not the innately most powerful kind that receives immortality, but a less, but more flexible breed.
So Domains don't really fit the Favoured Soul as the Favoured Soul is not a Priest (they can be, but it's not required) like a cleric will be universal viewed as a Priest even if they chose not to be involved in organized religion.
Jesus would be a Favoured Soul, so would the Antichrist and the Pope a Cleric, just for comparison sake.
Maybe I'm missing something. Where are you getting this from? Your bonus attack (and second bonus attack if spending a ki) use your monk damage, which is a d4 at third level. Not counting flurry (because you'd only have 3 total ki, and most monks spend ki on other things besides just flurry), you've have one attack at 1d10+DEX, and one bonus at 1d4+DEX.
Actually, according to Christian doctrine, Christ is God.Jesus would be a Favoured Soul, so would the Antichrist and the Pope a Cleric, just for comparison sake.
I just hope the Shadow Sorcerer and the Raven Queen warlock made the cut.
Flurrying with Kensei weapons would be very OP without some kind of drawback. They can two-hand a longsword for d10 damage, which would be 3x d10+Dexmod attacks right at 3rd level, far outstripping any other class.
The defensive Path of the Kensei benefit seems set up as a choice. The Kensei gets to either:
1) do a little more damage than most monks, by using a versatile martial weapon: one 1d10+dexmod attack and one 1d4+dexmod martial arts attack (or two extra attacks with flurry, all of this is at level 3)
2) do a little less damage than most monks, but gain +2 AC without having to use a bonus action: gain +2 AC for a turn and make two 1d4+dexmod attacks (or three with flurry, again at level 3)
At early levels they basically get +1 dpr vs other monk subclasses or +2 AC/-2 dpr. Later on the tradeoffs change around a bit due to martial arts damage die increases, but they basically always have a dpr advantage over other subclasses as long as they make attacks with their kensei weapon.
Maybe it doesn't seem like much, but +2 AC without having to burn the bonus action is a pretty big deal for a monk - they have so many other uses for bonus actions.