I don’t know if somebody’s compiled a list previously, but here we go:
Alastair (Khetar)
Amira (Leonis Empire)
Atlanta (Divinion Fields)
Avina (Ghulvania)
Azura (Merlantis)
Baba Yaga (Urskaya)
Brian the Lucky (Zaejin)
Dark Song (Grosh-Nak)
Dimetrexia (Darkstone)
Elwyn (Pan’s Vale)
Emperina (Khaziel)
Ferit (Karakoth)
Finley (Pridelands)
Gemhammer (Dhrak-Zum)
Herald of Chaos (Blighted Lands)
Herald of Torpor (Hellcrag)
Keghammer (Stormheim)
Lady Sapphira (Whitehelm)
Li’l Johnny Bronze (Blackhawk)
Luther* (Broken Spire)
Marid (Drifting Sands)
Penglong (Shentang)
Pride* (Sin of Maraj)
Prince Ethoras (Bright Forest)
Princess Elspeth (Silverglade)
Raven (Mist of Scales)
Rowanne (Forest of Thorns)
Scarlett (Maugrim Woods)
Shayle (Nexus)
Sparkgrinder (Adana)
Sunweaver (Wild Plains)
Tassarion (Glacial Peaks)
Tau (Sword’s Edge)
Tezca (Suncrest)
Tyri (Zhul’Kari)
Visk (Dragon’s Claw)
Vulpacea quest giver (TBD, future content)
*- (Luther is the NPC who accompanies you during the Sin of Maraj questline, but Pride is the Epic troop awarded for completing it.)