I hear a lot that people sometimes miss the character variety/options of 3.x/Pathfinder compared to 5E, but I've never really understood that. With very few exceptions, I haven't had any character ideas that I thought worked really well in 3.x/PF that couldn't be translated to 5E pretty easily, especially given a DM who was flexible about allowing homebrew or third party content. It's not always a 1-to-1 correlation, but it's usually "close enough" that the character feels pretty much the same.
So far, the biggest exception I've found to that, is Lachwen, my Badass Lightning Girl. Now keep in mind, she was originally a runekeeper in LotRO, so already a translation to tabletop is going to be a little wonky. (With the exception of bards, there pretty much aren't any D&D classes that can swap back forth between damage and healing the way RKs do. But in practice, I rarely played her as a healer, almost always going DPS. So when the time came to convert her, I simply dropped the healing all together.)
Now, I never got to play her on the tabletop, but I did stat her up for Pathfinder, and with the various splats (honestly I don't even remember which ones, but they are from Paizo books, I didn't use outside material), she worked really well. Affinity for the elemental plane of air gave her all the zappy-blasty she needed, especially with the ability to convert other elemental spells to lighting as desired. Fireball for instance, became lightning burst... waahahaaaa!
Alas, 5E doesn't really have a good "elemental sorcerer" setup– which I thought from day one was a strange omission. It has the draconic bloodline, which kinda-sorta does it, while also adding scales, wings, and a lot of other baggage. But my vision for Lachwen was always that she just bristled with elemental energy, kaboom!
The closest thing I've found, even from third party materials, is the storm sorcerer from The Sword Coast Adventurer's Guide, which in terms of fluff is exactly the same as her PF incarnation, right down to the tie to the plane of air. But the powers it gives are weird ones... randomly flying at 3rd level, for instance, and mostly-fluff minor weather control powers at 6th .
So that's how she's been built. I made her 6th level to be able to do an apples-to-apples comparison with her PF incarnation. I tweaked her a bit, making her half-elf instead the high elf she was in PF, partially for the CHA bump but also because Lachwen is not stately or refined in any way. If Obsidian is Rarity as a bard? Lachwen is Rainbow Dash as a sorcerer.
Lachwen Shimmerlight (CR 2; 450 XP)
Female humanoid (half-elf) sorcerer 6, chaotic good
AC 13*; hp 38 (6d6+12)
Speed 30 ft.
STR 10 (+0), DEX 15 (+2), CON 14 (+2), INT 12 (+1), WIS 8 (-1), CHA 17 (+3)
Feats Elemental Adept (Lightning)
Saving Throws Con +6, Cha +7*
Damage Resistances Lightning, Thunder
Skills Arcana +4, Athletics +3, Insight +2, Intimidation +6, Perception +2, Performance +6
Senses darkvision 60 ft., passive Perception 12
Languages Common, Draconic, Elvish, Primordial
Elemental Adept. Spells Lachwen casts ignore resistance to lightning damage. In addition, when she rolls lightning damage for one of her spells, she can treat a roll of 1 on a damage die as a 2.
Font of Magic. Lachwen can draw upon a wellspring of power, giving her 6 sorcery points which may be used to create spell slots or fuel her metamagic abilities.
Heart of the Storm. Lachwen is resistant to lightning and thunder damage.
Metamagic. Lachwen knows the Careful Spell and Distant Spell metamagic abilities.
Spellcasting. Lachwen is a 6th-level spellcaster. Her spellcasting ability is Charisma (spell save DC 14, +6 to hit with spell attacks). Lachwen knows the following spells:
Cantrips (at-will): dancing lights, fire bolt, lightning lure, prestidigitation, shocking grasp
1st level (4 slots): thunderwave, witch bolt
2nd level (3 slots): gust of wind, hold person, shatter
3rd level (3 slots): fireball, lightning bolt
Storm Guide. Lachwen may subtly control the weather around her.
Dagger +1. Melee or Ranged Weapon Attack: +6 to hit, reach 5 ft. or range 20 ft./60 ft., one target. Hit: 1d4+3 piercing damage.
Tempestuous Magic. Immediately before or after Lachwen casts a spell on her turn, she may use a bonus action to fly 10' without provoking attacks of opportunity.
*Ring of Protection
Soooo, yeah. Not exactly the same, but she's a workable facsimile– although I really miss that ability to change other energy damage to lightning. This version is more physical (running, jumping, climbing) than the Pathfinder one and less social, although she still has Intimidate and Performance, to create scary (or awesome) Tesla-style lightning displays and firebreathing routines. I also gave her fewer magic items, just 'cause that "feels" more 5E. She could use some bracers of defense or the like, tho.
If I were going to make her closer to the LotRO version (and had a willing DM) I'd probably change her tempestuous magic's flying to some sort of shocking bolt that stunned [number up to Cha bonus] creatures within 5' until the beginning of their next turn if they failed a Con save, to give it that same "I can escape being swarmed!" thing without randomly turning her into Supergirl for short hops. (But really, do you even need that, with thunderwave on the spell list?) Of course, that would have the side-effect of setting up the party rogue for free sneak attacks on dazed opponents, but it would have the saving throw as a counter to that (and keep Lachwen's feet on the ground). (I picture her hold person being very similar to that, a magic taser, basically.) But she's already got one splatbook thing going on as it is, and her skill proficiencies came from a third-party background (Mercenary) because none of the official ones really fit, so I wouldn't be surprised if a DM said no.
(In a "core only" game, she'd be draconic with a blue dragon ancestor and the Entertainer background. But she'd also have scales and eventually sprout wings, which is even less like Lachwen should be than this version is.)
-The Gneech, bzzaaap, bzzaaap
 Not totally useless, but how often is "make it quite raining in a 20' radius" going to be useful in most D&D games? I can at least see the ability to cause and/or cancel wind having use for dousing/spreading fires and the like.