Missing legendary type combinations

Normal:

1. Normal: Arceus, Type: Null, Silvally, Regigigas
2. Normal/Flying: None.
3. Normal/Fairy: None.
4. Normal/Fighting: Meloetta Pirouette Forme
5. Normal/Psychic: Meloetta Aria Forme
6. Normal/Grass: None.
7. Normal/Ground: None.
8. Normal/Water: None.
9. Normal/Dragon: None.

Water:

1. Water: Kyogre, Primal Kyogre, Suicune, Phione, Manaphy
2. Water/Ground: None.
3. Water/Flying: None.
4. Water/Poison: None.
5. Water/Ice: None.
6. Water/Psychic: None.
7. Water/Dark: None.
8. Water/Fairy: Tapu Fini
9. Water/Grass: None.
10. Water/Electric: None.
11. Water/Fighting: Keldeo
12. Water/Ghost: None.
13. Water/Dragon: Palkia
14. Water/Steel: None.

Grass:

1. Grass: Shaymin
2. Grass/Poison: None.
3. Grass/Flying: Shaymin Sky Forme
4. Grass/Fairy: Tapu Bulu 
5. Grass/Fighting: Virizion
6. Grass/Steel: Kartana
7. Grass/Dark: None.
8. Grass/Ice: None.
9. Grass/Dragon: None.
10. Grass/Ground: None.

Psychic:

1. Psychic: Mewtwo, Mega Mewtwo Y, Mew, Deoxys, Uxie, Mesprit, Azelf, Cresselia, Cosmog, Cosmoem, Necrozma
2. Psychic/Flying: Lugia
3. Psychic/Fairy: Tapu Lele
4. Psychic/Fighting: Mega Mewtwo X
5. Psychic/Fire: Victini
6. Psychic/Grass: Celebi, Calyrex
7. Psychic/Dark: Hoopa Unbound
8. Psychic/Ghost: Hoopa Confined, Lunala, Dawn Wings Necrozma
9. Psychic/Steel: Solgaleo, Dusk Mane Necrozma
10. Psychic/Dragon: Ultra Necrozma

Fire:

1. Fire: Entei
2. Fire/Fighting: None.
3. Fire/Flying: Moltres, Ho-Oh
4. Fire/Normal: None.
5. Fire/Dark: None.
6. Fire/Steel: Heatran
7. Fire/Water: Volcanion
8. Fire/Ghost: Blacephalon

Electric:

1. Electric: Raikou. Xurkitree, Zeraora
2. Electric/Flying: Thundurus
3. Electric/Steel: None.
4. Electric/Normal: None.
5. Electric/Fairy: None.
6. Electric/Ghost: None.
7. Electric/Fire: None.
8. Electric/Ice: None.
9. Electric/Psychic: None.

Fighting:

1. Fighting: Zamazenta
2. Fighting/Flying: None.
3. Fighting/Ghost: Marshadow
4. Fighting/Ice: None.
5. Fighting/Steel: Zamazenta Crowned Sword

Bug:

1. Bug: None.
2. Bug/Flying: None.
3. Bug/Poison: None.
4. Bug/Steel: Genesect
5. Bug/Grass: None.
6. Bug/Rock: None.
7. Bug/Water: None.
8. Bug/Electric: None.
9. Bug/Fighting: Pheromosa, Buzzwole,
10. Bug/Ground: None.
11. Bug/Fire: None.
12. Bug/Fairy: None.
13. Bug/Ghost: None.

Fairy:

1. Fairy: Xerneas, Zacian.
2. Fairy/Flying: None.
3. Fairy/Steel: Zacian Crowned Sword.

Poison:

1. Poison: Poipole
2. Poison/Dark: None.
3. Poison/Flying: None.
4. Poison/Fighting: None.
5. Poison/Ground: None.
6. Poison/Fire: None.,
7. Poison/Dragon: Naganadel, Eternatus

Ground:,

1. Ground. Groudon
2. Ground/Fire: Primal Groudon
3. Ground/Ghost: None.
4. Ground/Flying: Landorus
5. Ground/Dark: None.
6. Ground/Psychic: None.
7. Ground/Electric: None.

Ice:

1. Ice: Regice
2. Ice/Ground: None.
3. Ice/Flying: Articuno
4. Ice/Steel: None.
5. Ice/Psychic: None.
6. Ice/Ghost: None.
7. Ice/Fairy: None.

Dragon:

1. Dragon: None.
2. Dragon/Flying: Rayquaza, Mega Rayquaza
3. Dragon/Fire: Reshiram
4. Dragon/Fighting: None.
5. Dragon/Electric: Zekrom
6. Dragon/Psychic: Latios, Latias, Mega Latios, Mega Latias
7. Dragon/Ice: Kyurem
8. Dragon/Fairy: Mega Altaria
9. Dragon/Ground: Zygarde

Rock:

1. Rock: Regirock
2. Rock/Water: None.
3. Rock/Ground: None.
4. Rock/Steel: None.
5. Rock/Flying: None.
6. Rock/Electric: None.
7. Rock/Grass: None.
8. Rock/Psychic: None.
9. Rock/Ice:: None
10. Rock/Dragon: None.
11. Rock/Fairy: Diancie.
12. Rock/Fighting: Terrakion.
13. Rock/Poison: Nihilego
14. Rock/Dark: Tyranitar

Dark:

1. Dark: Darkrai
2. Dark/Flying: Yveltal
3. Dark/Dragon: Guzzlord
4. Dark/Fighting: None.
5. Dark/Fire: None.
6. Dark/Normal: None.
7. Dark/Ghost: None.
8. Dark/Steel: None.
9. Dark/Ice: None.

Ghost:

1. Ghost: None.
2. Ghost/Grass: None.
3. Ghost/Fire: None.
4. Ghost/Flying: None.
5. Ghost/Poison: None.
6. Ghost/Dragon: Giratina
7. Ghost/Fairy: None:

Steel:

1. Steel: Registeel, Meltan, Melmetal.
2. Steel/Ground: None.
3. Steel/Ghost: None.
4. Steel/Fairy: Magearna
5. Steel/Fighting: Cobalion
6. Steel/Flying: Celesteela
7. Steel/Dragon: Dialga

Flying:

1. Flying: Tornadus

Edit(01.12.2018): Added USUM and LGPE stuff.
Edit(25.12.2019): Added Sword & Shield stuff.
Edit (10.01.2020): Added Calyrex's Psychic/Grass.