Blood Phoenix

Fiery Death and Rebirth. When the poenix dies, it explodes. Each creature within 60 ft. of it must make a DC 20 Dexterity saving throw, taking 22 (4d10) fire damage on a failed save, or half as much on a successful one. The fire ignites flammable objects in the area that aren’t worn or carried.
The explosion destroys the phoenix’s body and leaves behind an egg-shaped cinder that weighs 5 pounds. The cinder is blazing hot, dealing 21 (6d6) fire damage to any creature that touches it, though no more than once per round. The cinder is immune to all damage, and after 1d6 days, it hatches with a new phoenix.

Siege Monster. The phoenix deals double damage to objects.

Legendary Resistance (3/Day). If the phoenix fails a saving throw, it can choose to succeed instead.

Illumination. The phoenix sheds bright light in a 60 ft. radius and dim light for an additional 30 ft.

Keen Sight. The phoenix has advantage on Wisdom (Perception) checks that rely on sight.

Limited Telepathy. The phoenix can magically communicate simple ideas, emotions, and images telepathically with any creature within 100 feet of it that can understand a language.

Fire Form. The phoenix can move through a space as narrow as 1 inch wide without squeezing. Any creature that touches the phoenix or hits it with a melee attack while within 5 feet of it takes 5 (1d10) fire damage. In addition, the phoenix can enter a hostile creature’s space and stop there. The first time it enters a creature’s space on a turn, that creature takes 5 (1d10) fire damage. With a touch, the phoenix can also ignite flammable objects that aren’t worn or carried (no action required).

Flyby. The phoenix doesn’t provoke opportunity attacks when it flies out of an enemy’s reach.

Magic Resistance. The phoenix has advantage on saving throws against spells and other magical effects.

Magic Weapons. The phoenix's weapon attacks are magical.

Blood Bond. While not typically being able to speak and only really being able to communicate simple emotions and pictures telepathically to those around it, having formed an extremely close relationship with a blood-hunter who during the rebirth process sacrificed some of his own blood and vitality to empower the phoenix. In doing so passing on some of his own powers and elemental rites, as well as the phoenix now being able to properly communicate its thoughts telepathically with the blood-hunter. The blood-hunter can now concentrate on the phoenix and see and hear what it does, while basically controlling it. While this is happening however the hunter can no longer hear or see anything in his normal body until disconnecting from the phoenix. He can however still move and talk.

Blood Hunt. Adapting to the blood-hunter's skill for the hunt of dangerous demons. He can now dim his own fire in order to turn an almost black color and instead of shining a bright light his feathers and fire now almost sucking light in from its surrounding area causing it to be almost invisible to an untrained eye. The only thing remaining bright are its glowing red eyes. Giving major advantage on stealth roles.

Blood Shift. After observing the style of its blood-hunter companion it picks up on his ability to sacrifice some of his own vitality to temporarily boost his abilities and increase his chances for survival. The phoenix can now sacrifice 25 hp (dropping it's max until returning to normal) to change its size. It can also now temporarily transform into a fiery version of any creature it or the blood-hunter has hunted down before.  

Multiattack. The phoenix makes two attacks: one with its beak and one with its fiery talons.

Beak. Melee Weapon Attack: +13 to hit, reach 15 ft., one target. Hit: 15 (2d6 +8) fire damage. If the target is a creature or a flammable object, it ignites. Until a creature takes an action to douse the fire, the target takes 5 (1d10) fire damage at the start of each of its turns.

Fiery Talons. Melee Weapon Attack: +13 to hit, reach 15 ft., one target. Hit: 17 (2d8 + 8) fire damage.

Fire Ray. Ranged Spell Attack: +6 to hit, range 60 ft., one target. Hit: 10 (3d6) fire damage.

Etherealness. The phoenix magically enters the Ethereal Plane from the Material Plane, or vice versa.

Arclight Touch. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 27 (6d8) lightning damage, and lightning jumps from the target to one creature of the phoenix's choice that it can see within 30 feet of the target. That second creature must succeed on a DC 18 Dexterity saving throw or take 27 (6d8) lightning damage.

3 Legendary Points Per Round of Combat

Peck. The phoenix makes one beak attack.

Move. The phoenix moves up to its speed.

Swoop (Costs 2 Actions). The phoenix moves up to its speed and attacks with its fiery talons.