Multiclass Help -- Sorcerer (Phoenix Sorcery) / ?


So, I've wavered back and forth between a few different character concepts for an upcoming campaign that will hopefully be starting sometime next month. The gist: think Pirates of the Caribbean meets Into the Badlands -- a circular chain of seven islands, each controlled by a warlord in a setting where humans fought against the demihuman races in a civil war two hundred years previously and lost. Elves are the most prolific, followed by dwarves, orc, gnomes & halflings, the half-elves and half-orcs, and tieflings. Humans are on the bottom of the proverbial food chain -- most of them are either hidden in isolated enclaves or slaves to demihuman masters. The island chain is relatively small -- two days to sail from one end to the other, and it would take a couple of days at most to traverse each island.

Our party: a human (variant) fighter/rogue who will be going swashbuckler; a tiefling (with some cosmetic dragonborn-esque scales) monk going Way of Shadow; a half-orc ranger going Monster Slayer; a moon elf (fighter or paladin, probably paladin), and a druid (unknown race or Circle).

And then there's me: my plan is to go predominantly Sorcerer with the UA Phoenix Sorcery origin. Assuming we go to 20th level, I ideally want to have 18 levels of Sorcerer to have the full range of Phoenix Sorcery abilities. My original thought was to go full-on Jean Grey and dip into Warlock (Great Old One) for 2 levels for Awakened Mind and a couple of invocations (I'm basing the build predominantly off of Tulok the Barbrarian's Jean Grey build from his YouTube channel): his build played on grasp of Hadar/repelling blast enhanced eldritch blast shenanigans with things like wall of fire, for instance.

My rolled stats are 12, 15, 16, 16, 16, 17 -- going straight half-elf, none of the variant listed options from SCAG because I think Skill Versatility (Acrobatics, History) is too necessary, so final stats to start (we are starting at level 2) are Str 12, Dex 16, Con 17, Int 16 (+1), Wis 17 (+1), Cha 19 (+2). Faction Agent from SCAG is the planned background (Insight and Investigation being the skills of choice). Sorcerer 1 / Warlock 1 would be where I'd nominally start (Sorcerer being level 1 for the Con saves, taking Arcana and Intimidation), and I've got a decent sketch of what spells I would choose and what-not.

My problem is that I'd only have four ASIs, and ultimately all four of them would be feats (and, admittedly, not entirely optimized): Ritual Caster (wizard), War Caster, Resilient (Wisdom) and Elven Accuracy (Charisma). Ritual Caster (wizard) might not be an optimal choice, but it would greatly expand my versatility by having most of the wizard list ritual spells, particularly since I'm going to be the only arcane spellcaster of the group. War Caster would make my Con saves for concentration checks more reliable. Resilient (Wisdom) would help with Wisdom saves (while also rounding up Wisdom to 18), and Elven Accuracy (Charisma) is mostly a choice from maxing out Charisma at 20 while also giving myself "super-advantage", after a fashion.

I also suspect that Great Old One patron wouldn't be the best fit -- Awakened Mind is okay, but I can do better with the message cantrip. And given that my Dex isn't likely to improve any, I'm thinking that perhaps Hexblade will be the better choice: this way I can maintain getting grasp of Hadar and repelling blast invocations for eldritch blast. but I'll also have proficiency in light + medium armor, shields, and simple + martial weapons, thanks to the Hex Warrior ability).

I won't lie: I've considered at least alternative to this: Sorcerer (Phoenix Sorcery) 6 / Warlock (Celestial Pact of the Tome) 14, though the only thing that sorta holds me back there is that I'm playing a Warlock (Celestial Pact of the Blade) in the campaign we're winding down on, and I don't want everyone to think that I'm just replaying the same concept again with minor tweaks.

I know that a lot of people feel that the UA Phoenix Sorcery is underpowered, particularly with several abilities reliant upon the Mantle of Flame ability (which only lasts one minute and comes back on a long rest), but I really want to give it a go regardless. So, I'm asking for help and suggestions: should I stick with what I have, go with either of my listed alternatives, or try something different and forget the eldritch blast shenanigans (like Paladin, for instance, or maybe a two-level Bard dip)? I just want to see what people come up with, and hopefully it will help ignite a proverbial phoenix spark in my head (yes, bad Phoenix Sorcery pun there, I don't regret it).