The original pictures seem to be those of a Japanese twitter account, which then made their way throughout the rest of the world through a series of retweets, reposts, screencaps and more.

We are in no way related to the leak, contrary to what some conspiracy theorists may believe, and have no knowledge regarding the identity of the person responsible.

We would also like to say to some of our more concerned readers that reporting this leak was a subject of great controversy within our staff, due to the grave implications involved with such a leak and the consequences of a report for both those directly involved with Konami and the people who are involved with us, the reporters.

It was, however, ultimately decided that due to the size of the leak and the rate at which it has spread across the rest of the internet, it has become realistically impossible for us to avoid doing so. We bear no ill will, and we kindly hope that nobody has any misconceptions.

Super Rares or Ultra Rares for NECH
NECH-DE000
CXyz Barian Hope
NECH-DE014
NECH-DE022
NECH-DE050
NECH-DE023
NECH-DE041
An unknown Effect Monster
NECH-DE052
NECH-DE064
NECH-DE021
NECH-DE059
NECH-DE054

All specifics of this card’s translations are unconfirmed
Virgil, Rockstar of the Burning Abyss
Level 6 LIGHT Spellcaster Synchro Effect Monster
ATK 2500
DEF 1000
1 Tuner + 1 or more non-Tuner monsters
You can only control 1 “Virgil, Rockstar of the Burning Abyss”. Once per turn: You can discard 1 “Burning Abyss” card, then target 1 card your opponent controls or have in their Graveyard; shuffle it into the Deck. If this card on the field is destroyed by battle or card effect: You can draw 1 card. You can only use this effect of “Virgil, Rockstar of the Burning Abyss” once per turn.

All specifics of this card’s translations are unconfirmed

Lanzephorhynchus
Level 6 WIND Dinosaur Pendulum Normal Monster
ATK 2500
DEF 800
Scale 7
Pendulum Effect: Normal Monsters you control inflict piercing battle damage.
Flavor Text:
Diese Sauriergattung hat eine Angriffstande entwickelt, die alles durchdringen kann, und is so dem Aussterben entgangen. Trotz ihrer Lanze ernahrt, sie sich weiterhin weitgehend von Fisch.
(“This species of dinosaurs has developed an attack that can pierce through anything, which allowed it to escape extinction. Despite their lance, they subsist largely on fish.”)

Source:
Team Nightmare
Duelist Groundz
Akialive on Twitter (Potential Original Source)
Nodoublex on Twitter