Arthas (Frostmourne) (RoC)

Alien Magic. Arthas casts spells from a different Universe.  They are unaffected by counterspell but Silence (as he must speak) and anti-magic zone's work.  His spells use Mana

Mana.  Arthas uses mana to cast his spells and his maximum is 117.  Arthas regains 58 on a Short Rest and fully recovers on a Long Rest.

Regeneration. Arthas regains 15 hit points at the start of his turn if he has at least 1 hit point.

Hero Armor. Add 1d8 to any Saving Throw you make.

Legendary Resistance (3/Day).  If Arthas fails a saving throw, he can choose to succeed instead.

Devotion Aura. Gives +3 to Saving throws to allies (excluding yourself) within 15 feet of Arthas. Does not Stack with Aura of Protection from the Paladin.

Orb of Frost.  Enemies hurt by Strong Swing or Frostmourne lose half their movement  and have a -2 to hit penalty until the start of Arthas' next turn.

Chaos damage. Lethal to Gods (they will die if they are reduced to 0 hitpoints by this type of damage). No one has resistance or immunity to Chaos damage.  If it hits an object, the hit is automatically a critical hit.

Multi-Attack. Arthas makes one Strong Swing and three Frostmourne attacks.

Strong Swing. Melee Weapon Attack: +11 to hit,  (4d6 + 7) Chaos damage. 

Frostmourne. Melee Weapon Attack: +11 to hit, (2d6 + 5) Chaos damage. 

Holy Light. Costs 25 Mana. Range 30 feet.
Heal a creature other than yourself for 50 hitpoints. This can also be used against anything with the Undead Template and it instead becomes an attack, +15 to hit dealing 75 Radiant damage.  

Resurrection. Costs 75 Mana. Range 30 feet. You call out to dead creature that has been dead for no more than a day, that didn’t die of old age, and that isn’t undead. If its soul is free and willing, the target returns to life with all its hit points

Divine Shield. Bonus Action. Costs 10 Mana. Until the start of Arthas' next turn gain +3 on all Saving Throws and +3 AC.