Infernal Bond.

You can summon 20th Century Boy Over Hell through your Pact Familiar feature. While bound, you gain resistance to fire damage and can use your bonus action to command it to attack. If it drops to 0 hit points, it vanishes in a burst of metallic flame and reappears after a long rest.

Stand Manifestation (1/turn).

As a bonus action, the summoner can partially manifest or retract the familiar. When manifested, 20th Century Boy Over Hell can make melee spell attacks using the summoner’s spell attack modifier and uses the summoner’s proficiency bonus for saving throws.

under hell of 20th century boy: The character may push away as many creatures equal to its intelligence modifier a number of feet equal to its proficiency bonus X 3, or the creature can focus the push on one creature multiplying it also by the characters intelligence modifier. The character can also pull the creatures using the same system as the push but inverse

Hell Driver (Melee Weapon Attack):
+7 to hit, reach 10 ft., one target.
Hit: 15 (2d10 + 4) bludgeoning damage plus 7 (2d6) fire damage.

Sin Resonance (Ranged Spell Attack):
+7 to hit, range 60 ft., one target.
Hit: 18 (3d8 + 4) necrotic damage. If the target is below half its HP, the attack deals an additional 1d8 psychic damage.

Over Hell (Ultimate, 1/day).
The familiar channels the infernal rhythm of creation’s end. As an action, it releases a shockwave of demonic sound and hellfire in a 30-ft. radius. Each creature of its choice must make a DC 16 Dexterity saving throw, taking 8d10 fire damage and 8d10 thunder damage on a failure, or half as much on success. After using this ability, 20th Century Boy Over Hell immediately vanishes back to its summoning realm for 1 hour.

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