- It seems like Sorey wouldn't be a water or wind seraph. The most likely element he'd weield is probably earth. However, this is purely going off his human appearance.
- Given his Bolt Tempest Mystic Arte, it seems more like he'd be lightning oriented (since it's implied Gramps was a lightning seraph by the storm he churns up at the game's start, and Symmone is a dark seraph, meaning there are more than just the four types).
- I think it was just because Dezel was already wounded, so he couldn't handle the strain on his body.
- Indeed, I never got the impression that the Seraph were at risk of dying from the final attacks; Especially since it seemed like no big deal when Sorey pulled the gun out to potentially fire at Mayvin previously.
- Not really. The Seraphims were at risk because Heldalf was full of malevolence and that would probably kill them once they were shot with that gun. Sorey killed Heldalf in time, so they survived, unlike Dezel who was fatally injured and was shot at a Hellion full of malevolence too. You can see Sorey's relieved face when they show up fine after he kills Heldalf. As for the situation with Mayvin, he didn't have any malevolence, so it was because of this that Sorey could shoot him at that fight. He hesitated there because, if the attack worked, then he would have to admit to himself that risking his friends' lives was the only option they had at the moment of defeating Heldalf. Mayvin says this himself while they are fighting.
- Zaveid and Sorey do speculate before the final dungeon that using the seraphim as bullets in the gun will kill them, since Zaveid points out that going after Eizen might "spend" some shots they need for the Lord of Calamity. Even so, in the end it probably helps that the seraphim were being used to disconnect Heldalf from Maotelus, the very source of purification. In other words, once cut free of the source of malevolence actively corrupting him, Maotelus cheated like hell to give the others a happy ending.
The game talks about different ages, and we see that Maotelus is supposed to have been gone for 200 years. Lailah says that it has been a long time since a Shepherd was alive, the book Sorey carries around implies the same, and no one in living memory mentions seeing the last Shepherd (Michael). Additionally, the earthen historia show a multitude of Shepherd working together at once against the Lord of Calamity, but Heldalf was only cursed ~20 years old?
- The Celestial Records were written by Michael, but he kept his identity anonymous, and because of this Sorey didn't know that a Shepherd was the one who wrote the book. Michael wrote that, the last time whe world had a Shepherd, was 200 years ago. This information was from his point of view, there was a Shepherd 200 years before Michael, but since Sorey didn't know that, he thought it was 200 years before the current era. As for the Lord of Calamity, there were tons of them before Heldalf, the people in that flashback were fighting against someone who turned into it before him.
- The world guidance book for Zestiria has a timeline for the ages and the events before the ones found in the game. Amongst them includes knowledge that the first Shepherd in recorded history not only founded a kingdom, but also became the first Lord of Calamity. It's also mentioned the continent the game takes place on has been invaded from other continents in the past.
How did Mikleo become a Seraph after the sacrifice? What dictates which humans or animals get turned into Seraphs or when? Sorey is said to be a seraph at the end of the game, and some of the Lord of the Lands and Trial Guardians were previously Shepherds, humans, or other animals.
- It is said in the game that humans with "special" deaths can turn into Seraphims. Humans with high spiritual power too. Mikleo was related with the previous Shepherd, so his spiritual power was probably pretty high even as a baby. If you want an explanation about why he is a water Seraph, then my guess is because he was almost burned to death, before Michael finished the job. Also, Sorey being a Seraph in the second epilogue is just a popular headcanon, but since he lost his physical body and had a strong spiritual power, it makes sense he would be a Seraph after waking up.
We see that even as a fledgling Shepherd, Sorey is able to enact the Armatus. This lets him stand against the armies of Rolance with ease, changing the course of battle and defeating more experienced fighters when the majority of his experience is hunting prickleboars, not battle. However, Michael, who is presumably a more experienced Shepherd who finished his journey and created a village, doesn't indicate that he has a spirit with him and doesn't drive off the invading Hyland forces.
- After he retired from being a Shepherd, the Seraphims that were with him went their separate ways, just like Lailah.
A Shepherd is anyone who interacts with the Seraphim after the Age of the Gods ended, when the ability of resonance became rare. Why is Rose not considered a Shepherd as well, considering her ability with spirits is comparable to Sorey's? We know that Alisha, as a Squire, had much weaker resonance, but Rose's is strong enough to enact the Armatus.
- Because Lailah is, currently, the one that makes the contract and decides who is going to be the new Shepherd. She saw Sorey first, but in the Alisha DLC Rose is the new Shepherd in his place.
- The Cardinal was already defeated in their battle. She was so weak at that moment that she wasn't even being able to move anymore. Sorey's intention while watching her was to see if there was a way to purify her, but then, when he saw that it was impossible, he decided to kill her before Rose did it. And nothing would have stopped him, since the Cardinal was only screaming there, without any strenght left. It would be easy to anyone kill her. Zaveid could kill hellions because the gun was taking his strenght and transforming it into power, he was just too weak to kill them by himself without it.
- That doesn't answer anything though. When Sorey kills Heldalf in the finale he does after Heldalf has been purified and is reduced to his original human form, and in the case of Maltran she chose to keep her Human form. In both these cases it was as a Human when they died but Cardinal Forton is in her Hellion form when Rose kills her. Even after being defeated she refused to be killed and in most scenes Sorey and Rose finish Hellion bosses when Armitized. So it still doesn't make sense how Rose killed a Hellion without the power of Purifaction or being Armitized. Siegfried is a special weapon so of course it would kill Hellions without Purification.
- Hellions can be killed without purification. It's just Sorey that refuses to do it at first. Zaveid, for example, killed that first hellion in his introduction scene and only after doing it, it went back to its human form. Regardless of their forms, the Cardinal was just weak that time, and not every Hellion has an armor covering their bodies, so someone can just stab one and kill them. As for Zaveid, he needed Siegfried to fight the hellions, defeat them and kill them all alone and, for this, he needed its power, to survive the entire fight too. In Sorey's case, the entire party fought against the Cardinal and defeated her, to a state that she couldn't defend herself. There isn't really a rule that says that Hellions need to go back to being human to be killed.
- At the very start of the Alisha DLC, Alisha gets attacked by a random soldier and finds out it's a Hellion because it's too strong. Rose comes along and one shots it. Most likely normal people cannot at all kill a Hellion since Alisha and Rose couldn't do anything about Hellions till they got the Squires pact. I assume Hellions with a human form could maybe be killed but still, Cardinal Forton was in her Hellion form so it seems that it's inconsistent.
- That scene was not killing, it was purification, though. You can see the blue flames when the Hellion is killed in front of Alisha. Plus, Rose was with Lailah (armatized) and Edna at that moment, so it's not like she defeated it alone. Sergei was also able to kill a Hellion with his men too, so anyone can kill them as long as they are strong enough to survive the battle.
- Lucas and his men were also able to kill some hellions, albeit they were hell hounds and not soldiers, like the ones Sergei took down. Though it should be noted that to Sorey, his squires, and the seraphim they're seeing the hellion form and not the dog or the soldier that Lucas and Sergei respectively see. So it could indicate while killing them the form of the hellion just doesn't matter.
- I think it was just laziness in the design of the whole scene. Like you said, the flashback was supposed to be some time ago, maybe years, but the entire guild looks the same age over there. That being said, they were mercenaries, so they had good fighting abilities already. Dezel possessing Rose's body helped them in transforming the guild, but they didn't say how exactly.
- They've been an assassin guild for 5 years to be exact. The reason for a lack of a change in design could be because Rose's character was made a year before the game's release, because there isn't even a reference for her younger self in the artbook.
- It's only been about 20 years, sadly the games inconsistent writing makes it hard to figure out. According to the story manual for it, Michael didn't write his existence into the Celestial Record, making people think a Shepard hadn't been around for many years.
- The game very poorly tries to Handwave it with skit in the final dungeon where the groups thinks purifying Maotelus might make the process of having a Squire not as taxing as before. It isn't explained any further.
- She does mention sometime late in the game that she saw a seraph, that she figured could have been Dezel, when she was a little girl. It could be that Rose originally had high resonance but she could have grown up in corrupt environments that made her lose it later in life as the game shows that a strong hellion's domain can cut off or make a person lose their resonance. Still doesn't really explain the Dezel stuff or how she wasn't see any of the seraphim before hand.
- As for the little girl genetics might be a factor as in that event involving her it's revealed that her mother was able to see the girl's hellionized form which caused her to scream "monster" indicating that she does have resonance and people with that may have gotten it from their parents.
- Rose always had high resonance, that never went away. What happened is she lost her faith. She took a grounded attitude during her later years and lost faith in things like Seraphim, and so, even though she was capable of seeing them, she didn't because she basically didn't want to (unconsciously). Once Sorey re-introduces the concept to her, she starts to freak out. I believe the reason why she's able to use the armatus is because of Dezel constantly possessing her body making her more used to it, but she was always capable of seeing Seraphim if she just willing to believe. If Rose didn't have a high resonance already, Dezel wouldn't have been able to use her as vessel to begin with. (And in-game, she does state that she remembers seeing Dezel as a child.)
- The way they planned to purify Maotelus is by using Siegfried to sever the bond between him and Heldalf. The problem was that they had no more "bullets" to use with Siegfried, and in order to gain extra uses, the seraphim fighting alongside Sorey had to use their life force, the same way Dezel gives up his life to sever the malevolence from Rose. By the time you face Heldalf in the main story or Eizen in the sidequest, you don't have any uses of Siegfried left beyond sacrificing your teammates. If Sorey wanted to use Siegfried against Eizen, it would require him sacrificing the lives of the seraphim fighting alongside him, meaning he wouldn't have the four shots needed to separate the bond between Maotelus and Heldalf. Even if they were okay with giving up their lives to save Eizen, it's an issue of priority. As mentioned, Maotelus is basically the God of this world, and Heldalf is an issue on a global scale, whereas Eizen has remained restricted to one mountain and hasn't caused as much trouble as Heldalf. Plus, defeating Heldalf without breaking the bond with Maotelus is implied to be a bad thing since it unleashes a corrupted Maotelus in the bad ending.
- Maotelus also hasn't become a dragon yet, just corrupted by malevolence. It's established that once a seraph turns into a dragon, their old self is pretty much lost. So Eizen can't be turned back by purification by any means.
- Maotelus is also the original source of the purification powers. They just needed to get him purified enough to think to use it and he could take it from there.