Ranger 2/Eldritch Knight 10 is solid enough. You could also consider Wizard 2 instead to really get as close to Kensai as you can, giving up the extra fighting style for access to Level 3 spells and evocation school for safe AoEs. Or Wizard 1 for the Level 3 casting itself and one level wherever you'd otherwise think is best. You already seem to know EK 10 is the best place to stop with it and have a good idea of what generally is good anyway so you can be confident with whatever you do here. The biggest pitfall here is just that it's not gonna be the most charismatic. Because the point buy is pretty strict medium armor is actually somewhat difficult to maximize the benefits of (especially if you want to boost your Charisma) unless you dig some strength out and either use finesse weapons (there's a pretty dang good finesse longsword) or rely on strength potions. If you don't want to Finesse I'd advise heavy armor and dumping dex cuz the game has some EXTREMELY strong heavy armor. Later on you'll have quite a bit more flexibility with equipment that will let you respec your stats SIGNIFICANTLY to better optimize (and that applies to any of your potential builds).
Sword Bard is probably gonna be the way to go with Fighter 2 as you'll get an extra Fighting Style and Extra Attack at level 6 to further benefit Action Surge if you want to be up in melee. It also has the Blade Flourish feature to do one of three extra things on an attack at the cost of a Bardic Inspiration use. Valor gets the extra attack as well but is more focused on supporting others with its combat inspiration feature. Lore Bard won't have much use here if your goal is melee capability.
Tempest Domain on its own isn't as much of a melee class. It's strong if you're gonna get up to shenanigans with Thunderwave and other Thunder/Lightning damage (especially with the Lightning Charge mechanic on certain equipment), but it's stronger with area control and damage than it is with sticking close and hittin' stuff or being hit. Level 8 is when it will get its big Melee attack feature and it's just a 1d8 of thunder/lightning when you melee weapon attack which isn't a lot at that point when you're on your way to huge spells competing for your action. On that note if you invest up to level 8 for that, you're just better off climbing all the way to 12 for the final feat/attribute score and to get your biggest possible spell slot. Shadowheart's sort of "default" is Trickery Domain which is different enough from Tempest that there wouldn't be much overlap unless you were particularly pressed for healing but you're free to customize her class however you like once you find a certain character. All that said, if you want a melee lightning theme, a good shout is Level 2 Tempest so you have an opportunity to max out thunder/lightning damage with your channel divinity (especially on crits), Level 6 Storm Sorcerer for a bunch of nice features it gets, and 4 in Thief Rogue (so you can get a second feat) will let you engage in unethical Shocking Grasp spam with quicken spell with an extra bonus action, and let you cause some extra AoE collateral damage any time you cast something stronger than a cantrip.
Bardadin isn't bad either, in this case you'd probably want College of Lore to diversify your spell list at level 6 rather than going Sword or Valor since Paladin will get the extra attack earlier at level 5 and they won't stack. Though the level split will end up being determined by whether you want bigger smites/slots or more Paladin stuff and that can also change which bard subclass is better. My recommend is Level 5 Paladin, 7 Bard will get you the most rounded setup with College of Lore and up to level 5 spells with an extra attack. Otherwise the split I'd run with other than that is Paladin 9/Bard 3 and I'd lean Blade Flourish again; down to spell level 4 but still lets you play around with Bard stuff while getting that sweet sweet Charisma synergy. -edit- Also I forgot, if you're worried about breaking your oath, Devotion is the goodiest of two-shoes and is quite easy to break, Ancients has a lot more room to breathe, and Vengeance is generally very hard to break unless you let some wildly evil stuff happen for no reason. If your Oath does break interesting things happen that you might still enjoy rolelplaying through so you don't gotta worry about being too strictly limited with your choices.
Can't really tell you which one is best for you though.
Last edited by Auric; 18/10/23 08:50 AM.