Why medium armor?
There are tons of guides out there for DW Magicka NB; for generally PvE game play
Bar 1 DW: Dark Cloak, Concealed Weapon, Sap Essence, Lotus Fan, Inner Light, Clouding Swarm
Bar2: Resto: Refreshing Path, Healing Ward, Funnel Health, Merciless Resolve, Inner Light, Veil of Blades
Pop Merciless Resolve (or the other morph, I switched because its going to proc after 4 light hits in the new update), Healing Ward, Switch bars Lotus Fan, Sap Essence and then decide how to burn them down. You might have to sub Veil out with Swarm after the update to keep a vampire ability on your bar.