Aura of the Artificer

A swirling of hexidecimal coding flow out from you and coalesces in a soft blue radiance in a 30 foot radius surrounding you.  All creatures of your choice within that area, when you cast the spell, shed a soft dim blue light in a 5 foot radius.  Other creatures have disadvantage on attack rolls against them, and they have advantage on all saving throws until the spell ends.  

Additionally, when a fiend or undead hits an affected creature with a melee attack, the aura strobes with a vibrant light.  The attacker must succeed on a Constitution saving throw or be Blinded until the spell ends.