jmartkdr2
Hero
I dunno, a warlock hexblade/interesting patron should work fine.I don't have a firm grasp of class balance in 5e because it's not my cup of tea... but I see some non-mechanical problems.
Some classes (Fighter, Rogue, Bard) have subclasses that are generally very much thematically compatible with eachother. Some classes (Sorcerer, Warlock, Paladin) have subclasses that are generally very much not. Others have mentioned that classes vary considerably in how much they get from the base class and how much they get from the subclass-- and this isn't merely a balance problem, it's a thematic problem as well.
It would require considerable reworking of classes and subclasses, but I'd like to see how it turns out-- I'd also like to see this system implemented (without multiclassing) where characters could take one class with two subclasses, or two classes with no subclass or the bare minimum subclass(es) for their classes.
And most of the sorcerer blends actually sound kinda interesting (storm dragon, divine wild magic, shadow dragon or shadow storm...)
But yeah, paladin oaths would get wonky.