Warlock · Tiefling
Kaelith uses Charisma for everything — Eldritch Blast with Agonizing Blast for ranged damage, but can hold her own in melee with a pact weapon when needed. Darkness + Devil's Sight is the signature combo for advantage on attacks while enemies can't see you. Pact slots recover on short rest, so don't hoard them. Hellish Rebuke is great as a reaction when something hits you in melee — punish them and step back next turn. At level 4, take the feat that fits your party's needs. If you're the only damage dealer, Eldritch Adept for extra invocations. If the party needs utility, Ritual Caster.
Warlock · Tiefling
Kaelith uses Charisma for everything — Eldritch Blast with Agonizing Blast for ranged damage, but can hold her own in melee with a pact weapon when needed. Darkness + Devil's Sight is the signature combo for advantage on attacks while enemies can't see you. Pact slots recover on short rest, so don't hoard them. Hellish Rebuke is great as a reaction when something hits you in melee — punish them and step back next turn. At level 4, take the feat that fits your party's needs. If you're the only damage dealer, Eldritch Adept for extra invocations. If the party needs utility, Ritual Caster.
Fighter · Human
Garrett is a Battle Master Fighter built around controlling the battlefield with superiority dice. Trip Attack to knock enemies prone for the party's melee to get advantage. Riposte for reliable reaction damage. Precision Attack to turn near-misses into hits on big targets. Action Surge + four attacks in one turn is devastating at level 5. Save it for when you really need to drop something fast. Fighter is the most reliable class in the game — no resources to manage, just solid damage every single round.