Mentioned

Zeref returns to Alvarez after a long absence and commences a Spriggan meeting having them all gathered around the ceremony table.
"Seven members..." Zeref speaks, looking around, "Despite notices, everyone has attended the meeting, I'm impressed."
"Actually, Sir Neinhart is also here, but didn't come. Oh well..." Yajeel said.
"That's all right." Zeref assures.
"No, it's not all right." Invel adjusts glasses, "Defying his majesty's orders is a disgrace to the twelve's name."
"Don't be such a stick in the mud, Invel." Ajeel said, grinning as he leans against the chair with feet on the table, "We can just start with those that are present. A small elite force would be nice anyway."
"Well, now that we're here. We have a two things to discuss." Zeref speaks up, with a calm smile, "The first, is our invasion of Isghar. The second, is about the individual who recently caused a common after winning a coliseum battle and denied the offer of joining my ranks. Someone mind telling me his name?"
Dimara and Serena only tense as they know who since they fought him and got injured in the process.
"The Ice Dragon Slayer, Sueong Ryuto." August answers after sitting down, "The moment he coldly declined the offer, Irene decided resorting to force, even sending Dimaria, Wall, and Serena to subdue him, but he got away. Along with that, he had help in his escape and took down a very small amount of our forces. Adding the fact that he injured Dimaria and Serena in the process." He finishes, which still tenses the two.
"I concur. One of the coliseum competitors, Tyrone Stadon, aided him and destroyed one of my puppets." Wall said, "Lucky I'm in this new one."
"Next time I see Sueong, he's gonna pay!" Serena said, very mad, "Having some nerve doing that to me."
"I'm the one who gets first dibs." Dimaria chimes in, having bandages under her clothes from the slash across the chest she received from sueong, "I'll take my time killing him next time."
"Wow, He sure did a number on you." Brandish teases, "You should've capture him in quick fashion, what happened?"
"Oh shut up, brandy. I just got caught off guard, that's all." Dimaria scoffs.
"All the more reason why I should've been the one to get the subduing job done." Ajeel brags, leaning cooling against the chair of course, grinning, "I wouldn't have been caught off guard by some petty tricks. Bringing him down would have been a breeze."
"Arrogant as usual, eh? Ajeel." Wall said, "The injuries he inflicted on those two is proof enough that you would have problems, especially taking into consideration that he fought evenly with lady Irene."
"Hearing that from a guy who's puppet got destroyed by someone weaker than him is funny... but fair enough I guess, but it'd still be a breeze." Ajeel replies, "I'm not weak like you three."
"Now you're gonna get it." Dimaria is offended.
"You fools. This is now time to be fighting among ourselves in front of his majesty." Invel speaks out, adjusting glasses, "Especially when we have important matters like the invasion of Ishgar."
"Invel's right." Zeref agrees, smiling calmly, "You guys can get revenge on Sueong another time when you get the chance, but for right now... we're finally about to begin our March upon Ishgar." He goes on to talk about that.
"That's still a hassle." Brandish sighs.
"Now don't say that, brandish." Zeref calm smiles, "You agreed to follow my orders, remember?"
"Agreed. My actions and feels are two different things." She replies, "Even if it's a pain, orders are orders."
"You say anything you think. That's why everyone hates you, Randi." Dimaria smirks.
"Least I didn't get injured." Brandish teases back, "And FYI, I hate them, actually."
"I see, well it's no wonder we see eye-to-eye." She said, letting it be.
"Good Serena, will scorching you're homeland be painful to you?" Zeref asks him.
The latter gets up and dramatically preaches, "Painful, it is... NOT!" He dazzle shines.
"Creep." Brandish insults, writes out, so is Dimaria.
Serena poses, "Thank you."
"Your majesty. We are now to commence the final war on Isghar."
"In short, our target is the body of your former lover." Wall said, "A truly sinful act indeed."
"Not quite, as the fairy heart is the form of magic, not a person. Plus that's not the only goal." Zeref then adds, "Ishgar will be wiped out. Humanity must be exterminated."
----Mage Guild(Fairy Tail): 
The guild is having a meeting and discussing the upcoming battle as well.
"Could you tell us about the enemy that we're about to fight?!" Lucy asks Makarov as him and Mavis stand in front of the room.
"Mm, good question. I'll relay everything that I know." He replies, staff in hand, "The Spriggan Emperors: Zeref, also known as the mightiest black wizard in Ishgar."
Natsu only keeps a serious face as he was just mentioned.
"And beneath him is an elite force, the Spriggan 12." Makarov continues, "I only met six of year during my year staying there. It's a rare region and quite large." He then adds the second, "Invel, the Winter General, who is Zeref's chief of staff and his chief administrator... Given his title, it's likely that he uses Ice based magic, but that's all the details."
"Ice..." Gray mutters, having a little interest at there being another ice mage.
Then the third, "Ajeel, the sand wizard that we previously encountered during our escape. He's one of the most aggressive twelve members."
"Him..." Natsu remembers, still maintaining the serious face.
Then the fourth, "Brandish, the Nation Destroyer. She isn't aggressive, but her power is enough to wipe out entire countries." Makarov adds.
"We encountered her before on Caracol Island. I believe she uses magic that can alter mass objects." Erza remembers the encounter with her.
Then the fifth, "Dimaria, the Warrior Queen. I don't know what magic she has, but she's a knight who's respected as a goddess of the battlefield."
"She's a Knight? Not a wizard?!" Erza sweat-drops.
"You're one to talk." Laxus tells her, sweat-drops too.
Then sixth, "God Serena, the mightiest of the ten wizard saints. He's a disappointment of a man in every word, but more than anyone, I know how powerful he really is."
"I still can't believe our top wizard saint is now our enemy." Lucy said.
"I wonder why he defected from Ishgar." Juvia wonders.
"I doubt there's anyway to learn unless he's asked directly." Panther-lily states.
"That dirty traitor is going behind bars after I arrest him." Gajeel swears.
Then the last, "August, the Wizard King. He's to be very wary of." Makarov sweats too, "From what I know, He's on a completely different level and possesses tremendous power that makes the others pale in comparison."
The sound of this stunned everyone and the atmosphere going cold.
"I heard that he can use all manner of magic from every region in the world." Makarov adds, "He might even wield more type of magic than Zeref himself."
Team Natsu is even stunned by this, gasping a little.
"Those are the six I have knowledge of." Makarov said before adding another major event, "There's also another thing that I learned." He grabs everyone's attentions, "Recently, A Coliseum battle royal was commenced and finished before Zeref returned to Alvarez."
"A coliseum battle? What for?" Mirajane asks.
"To find another recruit to join their ranks and be a Spriggan as well, trying to increase their numbers on us." Makarov replies.
"A recruiter? How would they possible pull that off?" Max asks.
"They would recruit the winner, the last one left standing out of 50 competitors." He replies and adds.
"Wish I could fight in that coliseum, no fair." Natsu mutter pouts a little.
"You want to be a recruiter?!" Lucy mutter exclaims dramatically.
"So who won it?" Erza asks.
Makarov reveals, "Sueong, the Ice Dragon Slayer. He froze the coliseum in quick fashion the second it began."
"!" Stunned, the guild is.
"Another Dragon Slayer?!" Macao and Warren exclaim dramatically.
"He froze that many competitors and won in seconds?!" Elfman exclaims, "Manly!"
"Didn't expect to hear this." Gajeel said, "I ran into him about half a year ago. Was too focused on the slave route incident to notice."
"You met him already?" Erza asks, which Gajeel confirms.
"He was also mentioned back in Tartaros by the Ice Dragon." Wendy adds.
"If he won... then that means he'll be our enemy?!" Romeo exclaims.
"Wait, did he really go join them?" Natsu asked.
"No. He turned down the offer to join the Spriggan 12." Ryu answered after getting onto the stage. 
"Ryu, how did your journey to the Alvarez Empire go?" Erza asked her childhood friend. 
"Very well." Ryu admitted. 
"And because of that, they tried using force to make him submit, sending three of the twelve, Dimaria, Wall, and Serena, to subdue him, but he still got away." Makarov adds.
"We should count ourselves fortunate he refused to fight on behalf of Emperor Spriggan." Ryu continued. "I was considering asking for his assistance in the upcoming war with the Alvarez Empire and saw firsthand what he can do after the Colosseum battles. He injured the strongest of the Ten Wizard Saints and nearly killed a member of the Spriggan Twelve. But that's not all. He also fought the creator of Dragon Slayer magic to a standstill." 
"What a powerful Dragon Slayer." Mavis said.
"That's crazy!" Happy exclaims.
"Wow, he might have better Ice control than you do Gray." Natsu eyes, kinda teasing.
"Humph, only because he's an Ice dragon slayer, on top of that, my Ice would be useless on him if we fought since he'll just eat it. so I'm not surprised flame-brain." Gray scoffs, hands in pockets.
"Injuring the mightiest wizard saint, on top of almost killing another Spriggan...?" Lucy said, same expression, surprised.
"Yep, he's definitely be bad news!" Jet and Drop exclaim dramatically.
Natsu shakes in excitement, "Yeah and It makes me want to fight him too!"
"Absolutely not!" Some of the guild exclaim.
"Show some restraint, would ya." Carla sighs.
"Well, he did kind of help in weakening the enemy so there's that." Erza smiles anyway.
"This gives us a better fighting chance." Wendy agrees.
"Yeah, We're definitely winning this, whether three of the twelve were injured or not." Natsu speaks of encouragement which everyone smiles.
"Agreed, We'll now devise our strategy." Mavis nods, "Zeref will come at us with a full army, including the last injured two of the twelve."
Everyone listens closely with serious faces, ready for anything.
"There's no doubt that we have faced disadvantages in the pass and that our foes is more powerful than anything we've faced before." Mavis then says encouraging words, "With the amount of courage and bonds that we have, we will prevail through this battle."
"Let's show them what our guild is made of!" Natsu shouts with a fist in the air
"YEAH!" The guild shouts in agreement.