User blog comment:Jopjopjop/Volume 20 Spoilers/@comment-24421137-20150719030548

Here is what I got information wise

Current facts known:
 * 1) Rizevim is defeated by Ise and killed by Fafnir.
 * 2) 666 Awakens.
 * 3) Ise gains a new power it's called =
 * 4) Rias gets the SM armor =
 * 5) Ravel and Riser are okay.
 * 6) The King Piece is revealed - main function is to strengthen only.
 * 7) Nidhogg, the final evil dragon, appears. He holds Issei's parents captive as he beats on Ophis who considers Issei a friend and didn't want to see him saddened, as well as needing to protect the dragon egg from Nidhogg's attacks. Nidhogg leaves when Crom appears and Ophis suffers critical injury.
 * 8) Asia gives a banana to Crom as it seems to be the favorite food for dragons as Fafnir and the four evil dragon's like it. (Bananas are life)
 * 9) Diehauser is revealed to be another Strada. By that it means, Diehauser only intention was to foil Rizevim's plans. He did this by using worthless on Rizevim's phenex tears, stopping him from healing. Also Diehauser kept Riser and Ravel as he knew the higher ups would probably attack them while they were healing, as they knew the existence of the King piece. The main reason however, for Diehauser's match against Riser, was that he wanted to figure out how the phenex tears work, so he could perform worthless on it, when the time was right.
 * 10) The Rating Games are corrupt. Ajuka explains that many shady dealings go on behind the scenes as some Rating Gamers use the king piece even though they are banned and they also fix matches.

Issei's Diabolos Dragon. The crimson armor turned into "organic". The plate armor's color has shades of red and black. The number of wings is now FOUR and each wing has a cannon stored inside it. Its power is so massive that even Rizevim's Sacred Gear Canceller is overwhelmed by it. Also all the jewels in the CCQ gains an ∞ mark on it. Also this four was achieved using Great Red's flesh and Ophis' powers. Ise also has a move for this form, when all four cannons are used in tandem, he unleashes an attack named "Infinity Blaster", the Infinity Blaster is quite powerful, Ise shot it from one side of Agreas and it envelope the entire skies of that region. Lastly it has similar features with Juggernaut Drive but there is no ominous aura at all.

Rias' Crimson Extinct Dragonar' It is the combined technique of Rias and Issei that was mentioned in v19. This combined technique grants Rias a Scale Mail of her own. Issei uses his Wyverns and they sync both of their auras. Once synced, the wyverns attach themselves to Rias to create a female version of the Boosted Gear Scale Mail.(Hopefully it doesn't look like the one in the anime.)

There is a King piece, and it is only given or even known to the higher-ups of the underworld. Ajuka has six of the ten, while the other four remain in the possession of the higher-ups, which consist of some of the rating games top performers (Diehauser had given his piece to Ajuka during his rating game with Riser). The king piece does not go inside someone like a regular evil piece would.

The abilities of the king piece allows a person to strengthen whoever he chooses, which can range from 10 times to 100 times or more. Due to this, the Devil Government has banned the use of the King Piece out of fear that Devils with evil intention will misused it, apparently the ones with the King Pieces right now are the ones that was handed one before it was banned by the Government. Also there is a risk in using a King piece. If a person that uses it is already overwhelming in power, the drastic increase can kill him.

If I missed anything at this point in time tell me so I don't have to repeat this >_>.