Regeneration. Anastraya regains 10 hit points at the start of her turn if she has at least 1 hit point and isn't in sunlight or running water. If she takes radiant damage or damage from holy water, this trait doesn't function at the start of her next turn.
Spider Climb. Anastraya can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.
Vampire Weaknesses. Anastraya has the following flaws:
Aura of Vampyr. Anastraya and all allies within 10 feet get +3 to all saving throws and can't be frightened.
Greater Steed. Anastraya's mount is the Winter Wolf Sköll. Anastraya controls it in combat. While Sköll is within 1 mile of her, she can communicate with it te1epathically. It disappears temporarily when it drops to 0 hit points or when she dismisses it as an action. Casting this spell again re—summons the bonded mount, with all its hit points restored and any conditions removed.
Order to Charge. As a bonus action, Anastraya can command an ally within 30 feet to move up to their speed and make a single melee attack.
Special Equipment. Anastraya has +1 Armor of Resistance (radiant), Vambrace of the Resolute, and her +1 shortsword, Steadfast Perdition.
Vambrace of the Resolute (requires attunement by a creature missing a hand) is a left-handed forearm guard made of black steel. It ends in a stump, though there is a permanent Mage Hand that stays in place at the end of it and the prosthetic allows for a shield to be attached if the user is proficient. The Mage Hand glows a pale lilac and can be used as a normal Mage Hand, moving off of the wrist for the full functionality of the spell. There is no concentration check needed to maintain it, it is immune to all damage, and it can be used to attack when attached at the wrist. Vambrace of the Resolute can also be used as a Bigby's Hand by disappearing from the wrist up to three times a day and requires no concentration checks to maintain. It regains all uses at midnight.
Steadfast Perdition has three charges. As a reaction, Anastraya can expend one charge to cast Compelled Duel on a target she attacks. Steadfast Perdition regains all charges each midnight.
Spellcasting. Anastraya is a 13th-level spellcaster. Her spellcasting ability is Charisma (spell save DC 16, +8 to hit with spell attacks). Anastraya has the following paladin spells prepared:
Multiattack. Anastraya makes two attacks, only one of which can be a bite attack.
Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one willing creature, or a creature that is grappled by Anastraya, incapacitated, or restrained. Hit: 6 (1d6 + 3) piercing damage plus 7 (2d6) necrotic damage. The target's hit point maximum is reduced by an amount equal to the necrotic damage taken, and Anastraya regains hit points equal to that amount. The reduction lasts until the target finishes a long rest. The target dies if this effect reduces its hit point maximum to 0.
Claws. Melee Weapon Attack: +6 to hit, reach 5 ft., one creature. Hit: 8 (2d4 + 3) slashing damage and 4 (1d8) necrotic damage. Instead of dealing damage, Anastraya can grapple the target (escape DC 13).
Steadfast Perdition. Melee Weapon Attack: +11 to hit, reach 5 ft., one creature. +1 Shortsword. Hit: 10 (1d6 + 6) slashing damage and 9 (2d8) psychic damage.
Lay on Hands. Anastraya can heal from a pool of 65 hp, which restores on a long rest. Has no effect on constructs.
Channel Divinity. Anastraya has the following Channel Divinity options:
Templar Reprisal. When a creature within 5 feet of Anastraya casts a spell, she can use her reaction to make a melee weapon attack against that creature.
Deathless Vanguard. After making an attack against a creature, Anastraya can expend one charge (out of three) from Steadfast Perdition to cast Compelled Duel on the target.
Strahd himself is only CR 15. It mentions she would be similar to Rahadin, which is only CR 10. And this doesn't feel like a CR 16 enemy. Otherwise, the lore seems good and it's nice to have a more powerful bride than a basic spawn.
I imagine that this is meant to be homebrew to go with a higher CR version of Strahd.
Exactly! Strahd is going to be a CR 20 in my game :)