Celestial Draugr Cryptguard

Undead Fortitude. If damage reduces the Celestial Draugr  to 0 hit points, it must make a Constitution saving throw with a DC of 5 + the damage taken, unless the damage is radiant or from a critical hit. On a success, the zombie drops to 1 hit point instead.

Celestial Beacon When creatures take radiant damage from the draugr, that creature cannot benefit from being hidden
Celestial Revival When the Celestial Draugr successfully uses its Undead Fortitude, it regains 10 hitpoints
Divine Blessing The draugr's attack can deal radiant damage instead of necrotic
Divine Light The draugr can emit bright light in a 20ft. radius and dim light an additional 20ft. This light counts as sunlight. This light banishes any non-magical or magical darkness.

Life Sense The draugr cryptguard can pinpoint the location of any living creature that that is within 120ft. of it. This feature does not detect Constructs.
Magic Resistance The draugr cryptguard has advantage on saving throws against spells and magical effects.
Turn Resistance The draugr cryptguard has advantage on saving throws against effects that would turn the Dead

Undead Fortitude Upon dropping to 0 hitpoints, the draugr cryptguard can make a Constitution saving throw with a DC equal to half the damagedealt(minimum 10). On successful saving throw, the draugr regains 1 hitpoint instead.
It cannot benefit from this feature if it took radiant damage or was turned on its its previous turn.
Innate Spellcasting
The draugr cryptguard's spellcasting ability is Charisma(spell save DC 14, +6 to hit with spell attacks)
At Will Detect Magic, Detect Good and Evil, Protection from Good and Evil, 
3/day each: Fear, Inflict Wounds, Counterspell, Dispel Magic, Ray of Enfeeblement, Guiding Bolt, Daylight

Multiattack. The draugr cryptguard can cast a spell and make three attack with its Grave Falchion. It can substitute any number of Grave Falchion strikes for a Grave Bolt.
Grave Bolt. Ranged Spell Attack: +6 to hit, 150ft., one target. Hit: 9 (1d10+3) necrotic damage.
Grave Falchion. Melee Spell Attack: +6 to hit, reach 5ft., one target. Hit: 8 (1d8+3) slashing damage + 5 (1d8) necrotic damage.