Turning my Character Into a Monster

(Hopefully this is the right place for me to post this, as I am attempting to homebrew a monster based on an existing one. If not, I apologize.)

I am suppose to be running my first homebrew oneshot and wanted to have my character make a cameo. However, I have no idea how my characters will react and wanted to be prepared with a statblock. However, there are no Celestial Warlocks that I could fond in the monster manual. I found one at the tight level for the campaign for 5 Level 7 players, but it is a CR7 FIEND Warlock and not a Celestial, let alone one with a dip in fighter.

Below is the description of the creature I would like to loosely base the final product on, as well as a link to my character’s page. Any constructive suggestions you all would be willing to provide would be extremely welcome. I have had great luck with the community in the past and hope for it to continue.

…

Warlock of the Fiend

Medium humanoid , any alignment

Armor Class 13 (16 with mage armor)

Hit Points 78 (12d8 + 24)

Speed 30 ft.

STR

10

(0)

DEX

16

(+3)

CON

15

(+2)

INT

12

(+1)

WIS

12

(+1)

CHA

18

(+4)

Saving Throws WIS +4, CHA +7

Skills Arcana +4, Religion +4, Perception +7, Deception +7

Damage Resistances Fire

Senses Darkvision 60 ft.

Languages any two languages (usually Abyssal or Infernal)

Challenge 7 (2900 XP)

Proficiency Bonus +3

Dark One’s Own Luck (Recharges after a Short or Long Rest). When the warlock makes an ability check or saving throw, it can add a d10 to the roll. It can do this after the roll is made but before any of the roll’s effects occur.

Actions

Multiattack. The warlock makes three Scimitar attacks.

Scimitar. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 6 (1d6 + 3) slashing damage plus 14 (4d6) fire damage.

Hellfire. Green flame explodes in a 10-foot-radius sphere centered on a point within 120 feet of the warlock. Each creature in that area must make a DC 15 Dexterity saving throw, taking 16 (3d10) fire damage and 11 (2d10) necrotic damage on a failed save, or half as much damage on a successful one.

Spellcasting. The warlock casts one of the following spells, using Charisma as the spellcasting ability (spell save DC 15):

At will: alter self, mage armor (self only), mage hand, minor illusion, prestidigitation

1/day each: banishment, plane shift, suggestion

Reactions

Fiendish Rebuke (3/Day). In response to being damaged by a visible creature within 60 feet of it, the warlock forces that creature to make a DC 15 Constitution saving throw, taking 22 (4d10)necrotic damage on a failed save, or half as much damage on a successful one.

www.dndbeyond.com/sheet-pdfs/Actionsparda_162701517.pdf

Honestly, you could probably get away with just swapping necrotic damage for radiant damage on all the features and call it a day. Maybe swap out a few of the spells for ones your character often used.

Swap fire resistance for radiant resistance.

Maybe swap out Dark One's Own Luck for Celestial's Healing Light feature? Healing could be nice if the party allies with your character.

I don't know what your character's proficiencies were, but consider swapping the statblock's to be better aligned with the character as well.

You can also pretty easily switch the weapon to be whatever weapon your character used, assuming it's a similar one-handed weapon.