Sanctum of Amyntok
The Sanctum of Amyntok is an Endless Spell utilised by the Lumineth Realm-lords, that summons a protective magical shield around the caster. It is based around the Aelven rune Yngra, which means protection - or imprisonment.  
The ground splits open around the mage, as the realm's life force springs forth in the form of a crackling shield. 
The magical shield deflects and turns baleful spells and attacks into nought but flashes of blinding light.