I am certain by now a handful have seen my replies to that post about Modi from another poster, but I would like to take the time to put together a comprehensive post about my opinions on Modi, my personal analysis, and general thoughts. Without too many "what ifs" about his potential as a person or character, and minimal speculation where possible.
So in this post we will be looking at Modi's presentation of himself in the 2018 game, what others say of him in Ragnarok, and his relationships with family as are observable in game. I will be injecting my personal views on the character, obviously, similar to the Magni post.
When we are introduced to Modi alongside his older brother Magni. Physically, Modi is the smaller of the two, having inherited less of the physical giant qualities than Magni. However, between them, Modi is basically a copy of Thor. His hair, eyes, and build come right from Thor, for better or worse. Usually worse, it seems.
Modi is very much the stereotype of an ignored middle child, with the high achievement older brother, and baby princess sister. Modi is mentioned last repeatedly by Thor, and I do fully believe that it has something to do with how he looks, and not necessarily his behavior.
It's repeatedly mentioned that Magni was the favored son, getting all the credit for rescuing Thor from rubble, when it was both him and Modi. Magni was the heir to Mjolnir for the longest time, being stronger, smarter, and generally "Better" than Modi. Part of this is because Magni is "blonder", according to Mimir. I mentioned in my Magni post that this favoritism could come from association to Sif, who was likely seen as a fine addition to the family, and her being blonde made others associate the blonde Magni with her.
Modi looking like Thor and bearing what seems to be the brunt of the abuse from Thor could be tied together. Modi even tries to emulate his father's clothing and tattoos. Even the mace he has, which is not a typical Norse weapon, if it was at all, mimics the appearance of Mjolnir.
Thor has intense feelings of self hate, referring to himself often as a destroyer, and he even says all he's good for is "pissing mead and killing".
Modi possibly reminds Thor of himself.
The disdain he feels towards Modi is likely not really about Modi himself, and more about Thor. Because it does seem he loved Modi, even if he couldn't express it due to his own hang ups.
It's clear Modi admires his father, dressing similar to him, styling his hair and beard similar to his, trying to emulate his hammer as best he can... And it seems up to the end, he was trying to make Thor see him and appreciate him and his efforts.
We also need to look at Modi's upbringing.
Thor and Sif were absent in the boys' childhoods from what we understand. They were drunk and abusive (Sif and Thor do recall kinder memories with the boys when they were young, but generally they seemed to be absent). This likely left Magni, a child himself, to fend for himself and tend to Modi. Modi likely spent a good chunk of his childhood with Magni.
He does clearly love his brother, panicking and being distraught when Magni is killed, implying they're somewhat close, at least for Modi.
Being raised by another child wouldn't have given Modi a good foundation for emotional regulation, which could very well explain his poor emotional control post Magni's death (along with fear around Thor's reaction of course).
However, being basically raised by Magni likely meant he was also abused by him, as Magni would likely try to imitate what Thor did, for better or worse. On top of the abuse he suffered growing up, Odin ensured the environment he grew up in wasn't a free one. In fact I wouldn't be surprised if Modi, and by extension Magni of course, were subjected to very strict rules by Thor because of Odin. Odin did not like his grandsons, calling them useless in the first interaction we have with him in the game.
It's quite likely Modi had severe control issues.
Living in the shadow of your older brother, having to do what he and your parents demand, being beaten repeatedly... It's not surprising to me that Modi seems aimless and a little lost after Magni dies. And it would explain his decision to attempt to kidnap Atreus and force him to be his new brother.
Modi wanted someone he could control for once, someone small and vulnerable like he was as a child. Because you know Thrúd was off limits in that regard.
Thor would have killed Modi had Modi done anything beyond brotherly teasing and messing about. (For the record, I think Modi treated Thrúd well, given the fact that it seems she misses him. I think Modi saw his tiny sister and wanted to be for her the brother he didn't have growing up. Modi's intentions, perceived or no, with Atreus as "his new brother" are formed in terror and heightened emotion.)
Fear seems to actually be a major component in Modi's character.
Let's examine his weapons and fighting style first.
Modi sports the mace and shield. The mace rarely is used in actual attacks, aside from lighting. He primarily bangs on the shield with it to summon his lighting and presumably to taunt. Where Magni charges in, Modi seems to try and keep his distance and remain defensive. Lighting lands sporadically around him, adding yet another shield of sorts to hide behind. He does not like facing things head on like his brother. I'd even argue that in the fight with him and Magni, he uses Magni as a shield to get to Atreus, letting the older Aesir attack Atreus's shield, Kratos.
We can also examine this defensive behavior in how he talks to others.
He's wildly, and even unnecessarily abrasive. He seems to enjoy goading people, particularly Atreus when face to face with the boy. He seems to put up a front of being confident and cocky, but I don't think he really is. It's more likely he's emulating the older or more favored relatives around him. Thor's combat confidence (which is well earned on Thor's part because he is a tough one to fight), Baldur's taunts and goading, and possibly even something of Magni's cockiness.
In his last moments, in his second to last encounter, when Magni dies... In those moments we see the facade slip. We see him for what he is: a cowering little boy.
Tl;Dr: Modi, like Magni, is a victim of abuse. There is no denying that, especially as one of his last experiences was being beaten by his father. But he was just as willing and likely to perpetuate the abuse because it's what he knew and he wanted to take out his grievances on someone smaller than him. He's a brat and a bit of a creep. But it is also very likely that inside, he is just a kid trying to emulate his idol, his father
