Umbreon (5e Creature)
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Small elemental, any alignment
Pitch-Black. Whenever the umbreon is subjected to necrotic damage, it takes no damage, and instead, all creatures within 10 feet of the umbreon must succeed on a DC 15 Wisdom saving throw or be stunned until the end of its next turn.
Innate Spellcasting. The umbreon's innate spellcasting ability is Intelligence (spell save DC 15). It can innately cast the following spells, requiring no material components:
Multiattack. The umbreon makes two assurance attacks.
Assurance. Ranged Spell Attack: +5 to hit, range 5 ft., one target. Hit: 6 (1d8 + 2) bludgeoning damage plus 10 (3d6) necrotic damage.
Guard Swap. In response to missing with an attack that has disadvantage, the the umbreon can reroll the attack without disadvantage. The next attack against the umbreon has disadvantage.
Umbreon are darkness elementals with powerful magical abilities. They draw their power from the moon and are weakest during the day, but can use the moon during the night to increase their power. They are one of the possible products of an evolved eevee.