Defensive Rune is a skill located in the Dark Magic (which can be found in the Sorcerer skill tree). Defensive Rune is a morph of Rune Prison.
Magicka Nightblades have one of the best sustained setups due to their cheap spammable skill Funnel Health/Swallow Soul. Nightblades also have great ultimate generation due to Soul Harvest and the Catalyst passive, which is especially great in trashfights as they can dish out Ultimates twice as fast as other classes. With sets like Master Architect they also shine, activating Soul Harvest and Architect results in a 35% damage boost.
This build is meant for Nightblades that want to run dungeons as a tank. It’s main focus is providing a decent amount of heals, and together with that a decent uptime of the Spell Power Cure buff on all allies in the team. I have made two setups in terms of gear. One is focussed on maximum support, giving that extra bit of penetration. The other is focussed on sustain and shall be a bit easier to play for the newcomers.