They're are special because they're like superheroes and have such an over the top backgroundstory.
This is all matter of perspective ...
What is so super about Astarion?
He after all is just pretty face (wich alone is quite ... eh, lets say questionable), who even tho its centuries old, spend all that time of his imortality just charming people with his look, and them lead them to his master.
He have no usefull skills, nor any super powers (maybe except his bite ... that is usefull), not even exceptional story ... he was just some guy of the past, who accidentaly meet Vampire, who made him his slave. Isnt that story you heared thousand times allready?
No? Oh, maybe its just me ... i spend too much time in World of Darkness social networks lately.
What is so super about Lae'zel?
She after all is just regular common soldier, with completely brainwashed head.
And that is basicaly all she is.
Yes, her race is quite rare and unusual ... but so would be our Tav, if we would be able to play Aasimar, Genasi, Tortle, Lizardfolk, or prehaps even Warforged.
She dont even have that bite and all her superspecial powers are Larian constantly trying and failing efforts to make impossible for players to steal her cool looking amor during tutorial.
What is so super about Shadowheart?
Just as Lae'zel she is brainwashed fanatic ... ok, maybe not as fanatical as Lae'zel, but still fanatical enough to be anoying, if you play Cleric of Selune.
Her special power is that she own a box. "OooooOOOOooooOOOOooo" xD
What is so super about Wyll?
Just some dude who god his ass kicked, while he was in the army (if Flaming Fist can even be called that) ... then he sign contract with a Fiend and went for revenge.
I can say with one hand on heart and another on Bible that i never, ever, EVER in all my 20y i play roleplay games heared more generic and boring origin story than this.
Yes, he is now known as a Folk Hero ... btw, exactly the background we can pick aswell ...
But what is especialy funny, and what i would like
a lot if that happened to be true in the end ... we dont really know if he even actualy
IS that hero!
Remember, all his fame and glory come after he signed his contract ... do we really know if he actualy slain all those creatures ... or did Mizora took shorter route and simply send some Bards to sing about "glorious and marvelous deeds of the Blade of Frontiers" ?
After all, his former captain (we meet her at Waukeens rest) calls him a fraud!
And finaly there is Gale ...
Okey, this one seems quite spectacular, no arguments here ...
He is still just 1/5 tho.
