Shadow sorcerer / undying warlock / bard ?!

[Foxydono]

So here is the concept. The character starts off as a shadow sorcerer. There could be plenty of reasons for this, a rebellious childhood or some tragic event that flipped the character over to the dark side. After being an angry rebellious adult he starts to make friends and learns the world is not all that bad. The character makes a 180 degree turn and starts drawing energy from the positive plane to redeem himself. The further the character walks the path of the warlock, the more it becomes evident that although he draws his powers from something good, the role he plays in society is still rather dark. Most of the warlocks he knows start dealing with lower-planar creatures and the character feels that this isn't the path he should take.

After some soul searching the character discovers the wonderful life of being a bard. He can help his friends, be accepted by society and be an overall good and happy fellow. This feels really good and he decides to walk to path of bard for the rest of his career. He can tell many stories of his travels and his career so far and the character tries to help troubled souls, so they find the right path again.

The character progression would look something like:
(2) Shadow sorcerer: get some nice metamagic and be hard to kill. Seems like a decent start, not to mention casting darkness and seeing through it.
(2) Undying warlock: +charisma to radiant/fire damage and two invocations, seems like a good deal as well!
(x) Bard: lore bard seems like the best fit for versatility, but it doesn't matter too much. A satire bard seems like fun as well.

As for a race I'd probably go with a Tiefling. The troubled youth and the strange path of life seems to fit the theme well. Maybe an succubus or incubus offspring? A high charisma would make sense and also charming and entertaining people would come natural to a character like this (when he or she overcomes his troubled past).

What do you guys think of the concept and the build itself? It doesn't have to be an optimized character, but if it's too weak that can be a problem. Any thoughts or suggestions are appreciated!

[SharkForce]

you need 3 sorcerer levels to get metamagic.

also, this is just me, but it feels a bit weird to plan out what RP events will happen to your character. this is a story, true, but it's a co-operative one where you don't control all the characters and events.

[Zippdementia]

How many levels do you have to work with? What level are you starting at? If it's level one, you are way overplanning. Hell, he might die in the first couple of sessions!

[Foxydono]

Ah yes, in any case I'll need at least 2 levels in sorcerer to cast darkness which seems like a good idea, so it's probably worth it to dip a 3rd level into sorcerer for metamagic. As for the second question: I'm starting off 1st level and the campaign probably ends at 15, but can't say that for certain of course. I realize that there is a good chance I'll be dying somewhere along the lines, but I'm an optimist!

I made another character concept before this one and I didn't like it much. Feels like I have a million puzzle pieces but it never fits together perfectly. But that's why 5e edition is so fun and balanced :)

But could this work in theory? I realize 'sorcerer 3/lock x' will be more powerful, but 'sorcerer 3 / lock 2 / bard 10' is still playable right?

[Foxydono]

After some thinking I've crystallized the path of the character a bit more. I'm not saying I will follow this path entirely, assuming I survive for so long, but it's more of a general outline.

So as I said I will begin with the shadow sorcerer (human variant). I may do a Tiefling though, still undecided. Stats: Strength (8) Dexterity (12) Constitution (16) Intelligence (8) Wisdom (10) Charisma (16). Feat: elemental adept (fire): or is spell sniper better to take? AC: 14 with mage armor. Saving throw prof: con+cha.
1) Shadow sorcerer: strength of the gave. Cantrips: fire bolt, minor illusion, prestidigitation, mage hand. 1st level: mage armor, sleep.
2) Shadow sorcerer: 2 sorcerer points to cast darkness. 1st level spell: chromatic orb.
3) Shadow sorcerer: 3 sorcerer points, 1st level spell: shield. 2nd level spells: misty step, scorching ray. Metamagic: subtle spells (sneaky caster) and Twinned (although the character only has 3 sorcerer points this can work out with some nice cantrips). I first thought of doing careful spell, but since the character is 'bad-ass' at this point that wouldn't make sense.
4) Undying warlock: cantrips: eldrich blast, friends, (sacred flame and light at will) 1st level: hax, command, burning hands. Resistance radiant dmg and +cha modifier to fire and radiant spells -> synergy elemental adept.
5) Undying warlock: 1st level spell: expeditious retreat. Invocations: devil's sight (doesn't fit perfect with the character, but you could say he harnessed the ability while being a shadow sorcerer) and agonizing blast.
- so up to this point the character is very versatile. Decent hp, a bit low AC, but with misty step/shield it's doing pretty well. Being able to cast eldrich blast and fire/radiant spells with +charisma modifier of +3. Decent constitution save (also for strength of grave) and being able to cast subtle and twinned spells.

6) Lore Bard: cantrips: vicious mockery, mending, 1st level: cure wounds, faerie fire
7) Lore Bard: jack of all trades! Too bad it's still only +2, song of rest fore more healing, 1st level: disguise self.
8) Lore Bard: prof in.. not sure will depend on the background and haven't decided on that yet. The same goes for expertise. Also, getting cutting word which is nice. 1st level spell: detect magic, 2nd level: heat metal, pyrotechnics
9) Lore Bard: finally 18 charisma! 2nd level: silence.
10) Lore Bard: font inspiration and 3rd level: bestow curse, fear
11) Lore Bard: 3rd level: dispel magic Addition magic spells: fireball (makes sense with the build) and counterspell (or maybe find steed?). You also get countercharm.
12) Lore Bard: 4th level spell: polymorph
13) Lore Bard: finally 20 charisma!! pew pew, also 4th level: freedom of movement.
14) Lore Bard: 4th level: greater invisibility and 5th level: mass cure wounds or greater restoration. And increased song of rest.
15) Lore Bard: 5th level: hold monster and magical secrets: contagion and banishment or wall of force?

The reason I chose a human instead of Tiefling was because of the feat. Given this setup and because I want to boost charisma it's kinda hard to come by. The spell selection and even this build is still up for debate. I do think it's viable do to it's versatility and because it are all full casters I can cast some spells (like fireball or eldrich blast) at a higher level to do decent damage even when multiclassing. Let me know what you think!