Bro, I love questions, so just ask away if need be.

Your character is more than likely to have a Familiar or acquire a Familiar at some point in the RP just because of his sheer amount of magical affinity. And each familiar bond is different and unique. Communication depends on what kind of bond was made and how much of each soul was given up. In the case of Ikio and Merek, whose familiar bond was "made from the heart" and is a 1:3 (Ikio gave up 25% of his soul; Merek gave up 75%) soul transferral, they're able to communicate telepathically, and Merek can share memories, emotions, and a whole bunch of other shit.

To explain... everything in the second paragraph, we'll have to first think of magical affinity as a hollow space within an individual's body. Some hollow spaces are larger than others. Only people capable of manipulating magic have these hollow spaces. Magic-users' hollow spaces have magic—not filled to the brim; typically, magic fills only half of magic-users' hollows. This is kinda why familiar bonds are formed: to fill each beneficiary's hollows. It's like covalent bonds, y'know? But now I'm digressing. The magic inside a magic-user's hollow doesn't deplete over time. It stays at the same amount for the entirety of their lifetime. The magic there is simply the amount of magic that they're able to manipulate. Hence why magic-users with more magical affinities can do more shit; it's 'cause they can have more magic, so they're able to manipulate a lot of magic to their bidding (with training and experience, of course. They're not gonna be able to manipulate all of this magic from the moment of their birth). After magic-users die, what magic they had returns to the Heart of Magic. But, see, here's the thing nowadays: there is no Heart of Magic, no home base for magic to go chill in when it's not inhabiting things' bodies. Magic completely left that place. It doesn't live there anymore. Hence why Ikio and Kalevi are, y'know, the New Heart, pretty much. 'Cause magic is chilling inside them now.

Now, we're finally on Ikio and Kalevi. So, one could say that these peeps' magical affinities are so fucking humungous that their entire bodies are completely hollow (from a magical perspective, obviously). Since Ikio has 70% of all magic from the Heart of Magic, he's filled to the fucking brim with magic. Kalevi is filled close to halfway. That's pure magic. People with high magical affinities normally have 5% magic, and they can pretty much set a quarter of the world on fire if they're able to manipulate all of this magic that they have. So, like... if Kalevi wanted to split the world in half, he could fucking do that. We've got anime protagonists, fam. They're OP. They're just not trained enough to know how to manipulate so much magic, and Ikio downright refuses to make use of any of it.

Now, to introduce more lore: all of magic is divided between Ikio and Kalevi. All. So that means, most likely, that the magic-users remaining don't have any magic inside their "hollows" and thus are unable to manipulate magic or do any sort of magical shit. Only Ikio and Kalevi can use magic. The sheer lack of magic in hollows that are supposed to have magic has led to many remaining magic-users losing their minds and living as extremely mentally unstable individuals. You'll see what I mean when I introduce Damiana and Irvine into the plot.

So, now I've introduced two ways for magic-users to go apeshit. Now, let's think of magical affinities as hollows with glass walls. When magic was out there shoving itself inside of people and mythical beings in search of a place to temporarily inhabit, it was shoving itself into hollows it couldn't fit in, so these hollows fucking shattered, resulting in the magic-users "breaking" in every way possible. The second way is when a magic-user has no magic in their hollows; they become empty and unstable.

I sure do hope that all of that makes sense. This is all word vomit at this point. I'm just trying my best to explain it as thoroughly as possible.

Yeah, don't worry, it makes perfect sense. They're good explanations, so I'm pretty sure I just about got it. I think my only remaining question is what going through each of the kingdoms has to do with sewing together the broken heart, but I feel like I'll probably find that out eventually. Unless there's stuff I have to know about that now, in which case, please do tell me.

Everything else I have to say isn't really questions, but, like. Do you want me to make a possible love interest for Ikio. I ask because I don't really have any ideas for side characters yet save for like, maybe a long lost sister or something but that might be too cliche. If you'd prefer him to have no love interest, though, then whatever.

Honestly, if you wanna make a love interest, you can do that, but whoever they'll be, they'll have to be benched for. so. fucking. long. 'Cause Ikio, as I've said, is just... allergic to vulnerability. I do want to focus more on his platonic relationship with Kalevi for now, but when Ikio's finally developed to be less mentally unstable, then love interests can literally start mitosis-ing into existence for all I care. As for the long-lost sister or something, I've... already stolen that cliche with the whole Damiana plot—

I think that you can start by making a few NPCs in Kalevi's kingdom? And then just developing whatever NPC you like and then moving out from there.

Yeah, alright. I'll try to help and think of some sort of excuse for that, then.

Thanks for the advice, dude! I'll probably try and do that, then. Tomorrow, though.