I've played through Sin Mark a few times now and I have developed a clear set of spells I buy. I couldn't help wondering what other people did, So I made this topic. The idea is, what's your spell system? Mine is;
Fire goes to Fire Arrow Earth and Bone goes to Bone Wall Storm goes to Storm Strike Fire and Earth go to Volcano once I have Fire Arrow and Bone Wall And if the opportunity arises, I'll get Arrow Storm
Fear and Arrow Storm are the only two I always get, Arrow Storm first though, since gathering the right runes for Fear is a little harder. Fear is low cost and keeps them from attacking. Arrow Storm does a good amount of damage for the mana cost.