Kingdom Hearts: Unchained χ [chi]
I think it's the first one, can't remember fighting him before in this game.
I've been playing the game a lot lately, and particularly, I binged this weekend on it. They had a 0 AP campaign on for a while on every single quest, so I could play as much as I wanted and even abuse stuff like Mythril Madness quests to upgrade Keyblades really far. They also had a super powerful Raid Boss on for Halloween and I literally gained 100 levels this past weekend from abusing it and the 0 AP campaign. And I've done at least 150 Story Quests this weekend too.
Though my patience is wearing thin a bit. I have terrible luck with Medal pulls (which is why I'm struggling against stuff like Cerberus), and SENA have been doing some dodgy, greedy stuff with the game, such as the recent case of false advertising with the Jack & Sally Medal. Not to mention just making certain medals much harder to get compared to Japan, such as the recent KH1 Sora/Riku/Kairi Medal.
Also the micro-transactions are way too expensive. Like, I can't complain about the game REQUIRING me to pay because I've gotten really, really far without paying a dime and have been able to do fairly well. But I rarely get to participate in Medal Pulling because most of my jewels go towards other things. If I could spend about €5 every so often for a chance at one or two pulls of the Epic Medal Carnivals, that'd be perfectly reasonable, but no, it's €15 for even one shot. Oh, and you know how they say that "if you don't get the featured medal in 9 pulls, we'll give it to you GUARANTEED on the 10th pull"? Well, the highest jewel pack costs €149.99 and it only gives you enough for 9 pulls. So you still have to spend another €15 to get a guaranteed featured medal (in the case of right now, I'd LOVE to get Illustrated Kairi because she's OP and breaks the game, but I don't have that kind of luck to get it cheap, or the money to just force a guaranteed pull for it).