Lillum Armor. Gain [roll]1d6[/roll] temp hp when you take damage from another creature.

Infernal Bloodline. In order to access your spells you must use a bonus action to activate your demonic powers, the process of transforming is painful take crit 1d4 fire damage each turn while transformed, while in this form you cannot use your battle axe. You must use a bonus action to stop using Infernal Bloodline

Soul Charged Spell Scrolls. Abaddon has spell scrolls that are charged with the souls of his late family, He MUST use a bonus action to enter Infernal Bloodline before he can use them, he cannot regain spell slots through any means.

Spellcasting. Abaddon is a spellcaster during his Infernal Bloodline transformation, though without his transformation his spellcasting is weakened. His spellcasting ability is 20/10(Spell hit modifier +10/+5, Spell save DC 18/13). Abaddon has the following warlock spells prepared:
Cantrips (at will): Chill Touch, Eldritch Blast, Frostbite, Poison spray, Thunderclap, Toll of the dead

1st level (5 scrolls): Cause fear, Hellish Rebuke, Hex, Protection from evil and good, Witch bolt

2nd level (5 scrolls): Earthbind, Mind spike, Mirror Image, Misty step, Shatter, Spider Climb

3rd level (4 scrolls): Enemies abound, Fear, Fly, Remove Curse, Summon fey, Summon Lesser demon, Summon shadowspawn, Summon undead, Vampiric Touch

4th level (4 scrolls): Banishment, Blight, Summon Aberration, Summon greater demon, 

5th level (3 scrolls): Dance Macabre, Enervation, Far step, Infernal Calling, Negative energy flood, Scrying, Synaptic static

6th level (3 scrolls): Circle of death, Conjure fey, Create undead, Eyebite, Mass suggestion, Scatter, Soul cage, Summon Fiend, True seeing

7th level (2 scrolls): Crown of stars, Finger of death, Forcecage, Power word pain

8th level (2 scrolls): Dominate monsters, Feeblemind, Maddening darkness, Power word stun

9th level (1 scroll): Foresight, Power word kill, Psychic scream, True Polymorph

Battle axe. Swing your battle axe twice per action

Action Melee Attack. Battle axe: +9 to hit, reach 6 ft., 1 target. Hit: [roll]1d12+10[/roll]  slashing damage. 

Unarmed strike: +10 to hit, reach 5 ft., 1 target Hit: 8 bludgeoning damage.

Infernal Bloodline. In order to access your spells you must use a bonus action to activate your demonic powers, the process of transforming is painful take crit 1d4 fire damage each turn while you are transformed, while in this form you cannot use your battle axe. You must use a bonus action to stop using Infernal Bloodline.

Retaliation. When you take damage from a creature that is within 5 feet of you, you can use your reaction to make a melee weapon attack against that creature.

Infernal Bloodline. When you take damage from a creature you can roar loudly, creatures within 10 feet from you must make a CON or STR save DC: 15 on a failed save the creatures get pushed back 30 feet, in a successful save nothing happens.

Abaddon can take 3 legendary actions, choosing from the options below. Only one legendary action can be taken at a time and only at the end of another creature's turn. Abaddon regains a legendary action at the beginning of his next turn.

Battle Axe Attack. (Costs 1 Actions). Abaddon makes one Battle Axe attack.

Misty Step. (Costs 2 Actions). Regardless of your transformed state you may cast the spell Misty step without expending soul scrolls.

Infernal Bloodline. (Costs 3 actions). You may cast a spell at level 5 or lower without using a spell scroll unless the scroll of that level has run out.

Abaddon can take 1 Mythic action, choosing from the options below. Only one legendary action can be taken at a time and only at the end of another creature's turn. Abaddon regains a legendary action at the beginning of his next turn.

Dual Axe Attack (Costs 1 Actions). Abaddon makes two Battle Axe attacks.

Eldritch Blast (Costs 1 Actions). Regardless of your transformed state you may cast the Eldritch Blast cantrip at its lowest level ([roll]1d10[/roll]).