N welp, I'm gonna be busy. Decided to finally make the Celtic Guardian / Gaia / Black Luster cards in YGOPRO. I ended up thinking of 15 cards, so this is my plan:
Archetypes
Celtic - Celtic Guardian, Obnoxious Celtic Guard, Flute of the Celtic Elf, Celtic Myrmidon, Unyielding Celtic Guard, Celtic Swords Woman, Celtic Defense Force, Celtic Elf, Celtic Elf's Pet Dragon, Faerie Blade, Celtic Village
Gaia Knight - Gaia The Fierce Knight, Gaia The Dragon Champion, Swift Gaia The Fierce Knight, Gaia The Polar Knight, Gaia The Mid-Knight Sun, Gaia Knight Force of Earth, Gaia Dragon The Thunder Chaser, Gaia Drake The Universal Force
Black Luster - Black Luster Soldier, Black Luster Soldier - Envoy of the Beginning, Black Luster Soldier - Envoy of the Evening Twilight, Black Luster Ritual
New Cards
Blue Flame (Spell Card) - If you control a face-up "Gaia Knight" monster, special summon 1 "Curse of Dragon" from your Hand, Deck or Graveyard in Defense Position.
Celtic Defense Force (Trap Card) - Target 2 "Celtic" cards in your Graveyard; add those targets to your hand.
Celtic Elf (Effect Monster, Tuner, Light, Spellcaster, Lv1, 0ATK, 0DEF) - When this card is targeted for an attack: You can negate the attack, and if you do, change the battle position of this card, then you can Special Summon 1 "Gaia Knight" monster from your Hand, Deck, or Graveyard. During either player's turn, when a card or effect is activated that targets this face-up card (except during the Damage Step): You can Special Summon 1 "Gaia Knight" monster from your Hand, Deck, or Graveyard. You can only use 1 "Celtic Elf" effect per turn, and only once that turn.
Celtic Elf's Pet Dragon (Effect Monster, Tuner, Wind, Dragon, Lv2, 500ATK, 1500DEF) - This card gains 300 ATK for every "Celtic" monster on the field. This card's name is also treated as "Curse of Dragon" while it is on the Field or in the Graveyard.
Celtic Myrmidon (Normal Monster, Earth, Warrior, Lv4, 2000ATK, 400DEF) - An elf who learned to wield a sword. He often struggles to guard castles and fortresses but makes up for it with his offensive merits.
Celtic Swords Woman (Fusion Monster, Effect, Earth, Warrior, Lv5, 2200ATK, 1300DEF) - 2 "Celtic" monsters. This card cannot be destroyed by battle.
Celtic Village (Field Spell Card) - All Warrior-Type monsters gain 300 ATK and DEF. "Celtic" monsters on the field cannot be destroyed by card effects.
Chaos Blade (Equip Spell Card) - Equip only to a "Black Luster" monster. It cannot be destroyed by battle or card effects. It gains 500 ATK for each Dragon-Type monster on the Field and in either player's Graveyard.
Chaos Blade Strike (Quick-Play Spell Card) - Activate only if you control a face-up "Chaos Blade": destroy all cards your opponent controls, then inflict 300 damage to your opponent for each card sent to the Graveyard by this effect, then return all spell cards in your Graveyard to your Deck and shuffle it. You cannot conduct your Battle Phase the turn you activate this card. You can only activate “Chaos Blade Strike” once per duel.
Double Dragon Lance (Equip Spell Card) - Equip only to "Gaia The Dragon Champion". The equipped monster is also treated as a Warrior-Type monster and gains 600 ATK and DEF.
Faerie Blade (Equip Spell Card) - Equip only to "Skilled Blue Magician". It is treated as a "Celtic" monster while equipped with this card. It gains 400 ATK and DEF. (This card is always treated as a "Celtic" card.)
Flute of the Celtic Elf (Spell Card) - Activate only while "Celtic Elf" is face-up on the field: Special Summon up to 2 Warrior-Type monsters from your Hand. Then, you can add one "Polymerization" from your Deck or Graveyard to your Hand.
The Gates of Chaos (Quick-Play Spell Card) - Tribute 1 "Gaia Knight" monster; Special Summon 1 "Black Luster" monster from your Hand, Deck or Graveyard (ignoring the summoning conditions). Then, add 2 spell cards from your Deck to your Hand.
Hell's Flame (Spell Card) - If you control a face-up "Curse of Dragon": inflict 300 damage to your opponent for each card they control.
Unyielding Celtic Guard (Effect Monster, Earth, Warrior, Lv4, 1400ATK, 1200DEF) - This card cannot be destroyed by battle with a monster that has 1900 or less ATK.
Now I just need to make and code them all. See ya in 4 years
If you want a sneak peak at the cards, here they are:
clicky
akiza and the twins need to appear too 
