If youre talking about personal preference,then my list is:
1.Lynn(self explanatory).
2.Alric(reminds me of guts from Berserk for some reason).
3.Oni(demon slayer FTW).
4.Veruk(IDK kinda cute).
5.Lilth(all for her).
In terms of gameplay:
1.alric(first free hero but arguably better than dragons).
2.Lynn (best dueler in the whole series).
3.Oni(cool abilities but falls behind heroes from other games cuz no hero points included in KR).
4.Veruk(dies a lot but good staller).
5.Lilith(op hero spell but the rest of her is just okay).