I hadn't even thought about the evil path angle before. That's actually pretty nuts how you basically lose nearly half the party just by doing that already. Even more that it's your only two sources of arcane magic if you aren't playing a class capable of casting that magic yourself.
I suppose it's generally fine for actions to have consequences, but it seems like playing with fire to do it with such a small cast of characters so early in the game. Similar stuff happens in WotR based on your choice of mythic path and handling of companion quests, but that game has a cast of about 12 companions and it all happens in the second half of the game.
