Both are hard to work well together. Because... - Wizard optimal build is the build that focus only on 1 main element (Like Dark Wizard , Earth Wizard , etc.) and also with same playstyle. So you can gear up and improve efficiency of both classes at the same time. - Shadowmancer is a Dark Wizard. Dealing Dark-Element damage from the shadows. And dealing low damage by compensate it tricky / burst playtyle for PVP. - Rune Caster focus heavily on Non-Element or Earth Element. Also casting type that would be work well with another caster wizard class.