So this deck is mostly copied over from "Gahena: The Desecrated Garden" by Arsenicroute978, with some marked differences:
Removed cards:
Inferno Reckless Summon - Mostly because this doesn't make sense? This is a Highlander deck so why does it have a card that only summons cards with the same name as an already special summoned monster?
Magical Contract Door - Personally, I don't want to give any of the spells to the opponent, either because they'll become dud cards or because I'll need them myself (not to mention they might end up helping the opponent).
Vanity's Ruler - I dislike this card. About the only reason it's gone.
Darklord Descent - The chances of me having Darklords of the same level as an opponent's monster is a bit too low for my liking compared to what I've added.
Celestial Transformation - While I see its uses for Tribute summoning by adding monsters on the field, I feel like I have better options in that regard.
Added Cards:
Celestial Knightlord Parshath - The Sanctuary in the Sky and The Sanctum of Parshath both work well in this deck in general, and Celestial Lord only supports it further. The ability to change out cards with Fairy monsters in the deck, especially with the methods I have for moving cards from the graveyard, is fairly powerful, and so is the ability to immediately replace a fallen Fairy Monster.
The Sanctuary in the Sky - Mostly to activate the power of Celestial Knightlord, but still a useful card nonetheless.
The Sanctum of Parshath - More directly useful than Sanctuary in the Sky, but also takes up a spot on the Spell/Trap zone instead of the Field Spell zone. Good for returning Fairies in the deck and getting back the one protective Counter Trap of the deck, especially since you put them all on the top of the deck.
Forbidden Droplet - Gotta have a staple in there somewhere, and it is part of the theme and archetype.
Grapha, Dragon Lord of Dark World - Exceptionally good card with the mechanics of the deck - destroys opponent's cards when discarded from the hand, and denies resources for the opponent if destroyed by the opponent. Sure I won't be able to special summon it by its effect, but even Tribute summoning it wouldn't be too hard + it would support the effects of Darkest Diabolos.
Darkest Diabolos, Lord of the Lair - Amazing Anti-Kaiju counter, easy to summon (at least in this deck), and capable of draining resources from the opponent.
I feel good about this deck, personally, which means I'll hard-brick and lose immediately. RNJesus help me...