Starting at level one, Giant Red Demons have 10 feet of darkvision. Every level this amount increases by 10, resulting in 200 feet of darkvision by level 20.

Starting at level one, Giant Red Demons naturally have large sickle-shaped claws capable of doing 1d4 slashing or piercing damage. At level 2, the damage increases to 2d6. At level 3,the damage increases to 3d6. At level 4 the damage increases to 4d10. At level 5 the damage increases to 5d10. At level 6, the damage increases to 6d10 + 2d4. At level 7 the damage increases to 7d10 + 3d6. At level 8 the damage increases to 8d10 + 4d8. At level 9 the damage increases to 9d10 + 5d8. At level 10 the damage increases to 10d10 + 6d8. At level 11 the damage increases to 11d10 + 7d8. At level 12 the damage increases to 12d10 + 8d8. At level 13 the damage increases to 13d10 + 9d8. At level 14 the damage increases to 14d10 + 10d8. At level 15 the damage increases to 15d10 + 10d8 + 2d6. At level 16 the damage increases to 16d10 + 10d8 + 3d6. At level 17 the damage increases to 17d10 + 10d8 + 4d6. At level 18 the damage increases to 18d10 + 10d8 + 5d6. At level 19 the damage increases to 19d10 + 10d8 + 6d6. At level 20 the damage increases to 20d10 + 10d8 + 7d6.

For all levels, Giant Red Demons get a +8 to hit with these claws. This does not increase by level, unlike the damage.

Starting at level 6, you can use your action to exhale destructive energy with the appearance of orange flame. When you use your breath weapon, each creature in the area of the exhalation must make a constitution saving throw. On a successful saving throw, they suffer 10d8 fire damage, on a failed saving throw, they take 10d10 fire damage and are knocked prone. Giant Red Demons can use this ability 5 times, this counter can be recharged after a short rest.

Giant Red Demons have complete immunity to fire damage, and will not take any damage from attacks of that type.

Every time you level up, your strength modifier increases by 1, and the limit to your modifier's size is removed.

You get a +10 to intimidation rolls.

Starting at level 5, you can use your bonus action to grow large leathery wings half your body's total height in wingspan and fly to up to 120 feet away either up into the air or in a straight or diagonal line in parallel with the ground.

You can use your action to summon a 50 feet long flaming whip and make a Melee Weapon Attack: +14 to hit, reach 30 ft., one target. Hit: 15 (2d10 + 14) slashing damage plus 10 (3d6) fire damage, and the target must succeed on a DC 20 Strength saving throw or be pulled up to 25 feet toward you.

You can use your bonus action to force every creature in a 30 feet radius around you must make a Wisdom saving throw or be brainwashed onto your side and turned Chaotic Evil for 2 turns or until they are knocked unconscious. They also gain your Leathery Flight, Demonic Immunities, Hellish Tyranny, Destructive Breath, and Darkvision traits for the duration of this action.