Archangel

This platinum blade gleams with a Divine radiance held within. Forged long ago for the first Tiefling Paladin to free his people. After his death, it passed into the hands of a Dragonborn Paladin who used it to found an Order of paladins in the wake of a cataclysm to bring order to the world. With that order it has stayed, choosing a new wielder in times of great crisis. It was lost 50 years ago after being falsely taken into battle with a wielder it had not chosen, and was corrupted into a weaker, but vile version of itself. Now recovered and restored, it has found its way to your hands, and the Divine spirit within is eager to do the good work once more. 

Mythic Edge. You gain +4 to attack and damage rolls with this weapon. When you roll a natural 20 on an attack roll, you recharge your channel divinity if you have used it. If you have your channel divinity charge(s) or are a class other than Cleric or Paladin, you instead gain 10 temporary hit points. 

Divine Radiance. The weapon sheds bright light in a 15-foot radius. Fiends and undead find the weapon's light disconcerting and painful, even if they can’t see it, and have disadvantage on attack rolls made within the weapon’s radius of bright light. You have resistance to Radiant damage. 

Solar's Arsenal. This weapon does an extra 7 (2d6) radiant damage to any creature it hits or 11 (2d10) radiant damage to Fiends and Undead. As a bonus action, you can transform this from a Longsword into a Longbow, and you are considered proficient with this weapon. Its range is 150/600. When you attack with this weapon, you can use your Charisma modifier instead of your Dexterity modifier for the attack and damage rolls. This weapon generates its own ammunition and cannot use other forms of ammunition. While in its bow form, Archangel deals radiant damage instead of piercing. While Archangel is in its bow form, and you are a Paladin, you may smite with it on one attack per turn. You can change this weapon back to a longsword as a bonus action.

Archangel's Virtue. Your Charisma score is increased by 2. Archangel can cast the spell aura of life on you once per day. You decide when the spell is cast, and Archangel maintains concentration on it so that you don't have to. If you take damage from an area of effect spell or attack, Archangel must make a concentration check with a +15 modifier if it is concentrating on Aura of Life. 

Tyr's Justice.  You have advantage on Wisdom (Insight) checks to determine if a creature is lying to you. You are immune to any spell or effect that would charm you. You cannot be disarmed of this weapon forcefully or by magical means. You may summon Archangel to you with a bonus action from any distance, even across planes. However, Deities and other planar rulers can prevent this weapon from appearing in their presence or anywhere within their domains.

Sentience. Archangel is a sentient, lawful good item with an Intelligence of 20, a Wisdom of 22, and a Charisma of 28. It has hearing and dark vision out to a range of 120 feet. Archangel is inhabited by the previous Solar of Tyr, who volunteered to be placed within the weapon and serve as a guide to those who wield it. The sword communicates telepathically with the creature wielding it. 

Proficiency with a Longsword allows you to add your proficiency bonus to the attack roll for any attack you make with it.

Notes: Bonus: Magic, Damage: Radiant, Immunity: Charmed, Bonus: Charisma Score, Resistance: Radiant, creature the sword deems worthy, Damage, Combat, Warding, Versatile, Sap