Okay so we got 3 right now with 1 more that we know nothing about.....
We likely know of more. For one, Kindred is also a spiritual demigod, although one representative of a very powerful truth to Runeterra, and worshipped in the Freljord, their cult obviously transcends the Freljord but their local interpretation would likely factor into their legends and mythology even if not considered direct "siblings" to the others. We see examples of their worship in sources such as Ashe's VO and in Voice from the Hearth:
We would minister the Rite of the Lamb to our elderly and wounded, and the rest of us would dance with the Wolf. It would all be over by morning.
In Silence for the Damned we are told:
Udyr removed his cloak. Then, prepared by his evening meditation, he walked through his forms: the Undying Eagle, the Clever Lynx, the Iron Boar, and a dozen more spirit beasts. He paused when he assumed the aspect of the bear spirit. With perfect control, he matched the shape of the giant beast looming above him. Then, finally, Udyr changed from the bear into its sworn enemy, the spirit of fire, hearth, and forge-the Great Ram.
Clever Lynx, I believe, we have no further info on but this Iron Boar feels to me like the same boar demigod mentioned in Tryndamere's biography:
Tryndamere came into the world knowing only the harshness of survival, for the frozen steppes where his clan made their home never truly thawed. Though they praised all the Freljord's old gods, as well as the Cult of the Three, they prayed most often to a spirit-deity known to ravage the tundra-a hearty and unkillable tusklord.
(...)
Some in the clan knelt, believing that their boar-god stood among them.
Realms of Runeterra's Freljord story (A Good Day) also mentions another deity: a two-headed raven.
Many of his bone fetishes were carved in the likeness of gods and spirits of the north, and Vrynna wondered if it was they that spoke to him. Some of those gods she recognized --the Ice Phoenix and the Seal Sister among them-- while others she did not, such as a ram holding a hammer and a two-headed raven.
The sphere of influence of this deity is unknown. The fact that he has two faces, however, makes me think of "two-faced", which implies trickery and deceit, and the fact that he is a raven "times two" recalls to me Odin's ravens in Norse mythology (Huginn and Muninn, Thought and Memory) which could imply connections with knowledge, wisdom and fate.
Nunu's color story (Stone Cold) also mentions another important mythological being although how related it is to the others is unknown (but Anivia seems to hold Avarosa in high esteem judging by her interactions in LoR, despite the Iceborn Empire having seemingly fought against her kin):
I remember one song, a myth about how Avarosa healed the turtle that carries the sea, by giving it a big kiss! But I don't want my first kiss to be a statue. I make Willump kiss 'em just in case, and watch as the stone gets stuck to his fur.
As for:
I was wondering if she was a modern champion would she have also been a humanoid? Still an icy phoenix thing but shaped as a humanoid?
To be blunt, Riot's designs in the past year or two haven't exactly pushed the envelope. Kai'sa and Neeko are to me the most notable examples of characters that I would expect to look significantly different (given Void influences and Neeko having been from a supposedly very isolated and not too human Vastaya tribe, you can make the argument she is shapeshifting however). So, if you want to be cynical perhaps, they may not have been willing to make a champion like Anivia (a full on bird, which likely lacks the wider appeal of something like Yuumi) in modern times.
With that said, the Freljord as a whole is big on animals in general so I don't think her current visual design clashes with what would be expected or possible in that cultural paradigm nor would I want it to change.
Also have we heard anything regarding the Seal sister? I mean we know about it but do we know any details like what her name is?
The fact that we only know of her title, and a very generic title at that, is intended. The Seal Sister has been nearly forgotten, to the point where Ornn's writer said even he may not know exactly what happened to her. And remember that these are spiritual beings innately reliant on the culture they're in and that may wax and wane depending on how prevalent their worship/ideals/symbolism is at a given time.
We know of the Seal Sister only as Seal Sister because that's almost all that remains about her. It'd be like most Freljordians saying Ornn was the "ram god", it's not descriptive at all and is an indication of how their importance has decayed and how forces like Lissandra have been systemically sabotaging old god worship in favor of their new Three Sister oriented mythology. Only the most dedicated and conservative tribes have managed to preserve bits about some of them. The Cult of the Three Sisters has been sabotaging them for millennia.
For what it's worth, we have the following bits. From Nunu:
We've told the tales of iron forged, we've cowered at the thunder's roar, but if you sail, the sister seek. Seal sister from the ocean speaks! Willump, I want to meet her!
From From the Ashes:
And yet here he was, casting her remains to the bitter winds with a prayer to the Seal Sister, alone but for his thoughts.
From Lost Tales of Ornn:
But when sailors rub blubber on their faces and think about the Seal Sister, whose true name is forgotten, they are protected from the icy ocean winds.
Also any thing on who their parents are? Maybe they are gods of the Freljord and magical beasts, or maybe there is some lore on demigods in runeterra that explains where they come from?
To be clear to other comments in this thread, the term "demigod" is not used in the sense of half-divine here, it is used in the sense of "lesser deity" so as to partially distance it from notions of omnipotence and of "godhood" as some absolute. Even Aurelion Sol has been described as a demigod (although it is worth noting some of the larger cosmological parts of the setting have likely changed since) and the question of "what defines a god" is a recurring one.
The term "sibling" is also not used as a direct familial connection (ignore the Ascension reference there, the idea has since been changed), it is simply how mankind has interpreted and framed those ideas. "Fire is brother to Ice and Storm" sounds a bit "silly" when put so bluntly but they are similar forces to mankind and that's how the culture interpreted them and likely shaped them. Similarly, they are all spirits who likely came about via similar processes. They don't seem to have a common parentage besides the world itself (and then you can start asking questions about which entities in the setting so far are intertwined with life or the world as a whole) but, ultimately, it is up for the Freljord and its culture to create myths regarding these beings and how they relate to one another.
As for where they come from, the partially outdated Vastaya dev blog still offers a very good explanation as to what spirits and the Spirit Realm in general is:
Going back to Tahm Kench, we had been working with the notion that part of Runeterra's magic related to the spirit world seen in Shen's lore. This was a mirror world where the spirit of every living thing and every of type of thing exists. The souls of every person, the spirit of animals, the essences of species and of locations, elements, and even ideas exist in that dimension as powerful forces, which interact and create a type of magic in Runeterra. Furthermore, we knew the spirits from this place were not truly restricted in form. Tahm Kench and Kindred are not of our world-their appearances in the material realm are illusionary. They are creatures of pure magic who manifest under specific rules, but do not have a true shape or physical body like we do.
Keeping the earlier links about spirit gods in mind, our Freljordian demigods have two likely origins: the first is that they were brought to life by mankind and their stories, as faith/emotions/belief/worship is a powerful tool for shaping human minds and, as such, a powerful tool for shaping the Spirit Realm, which is the realm of thought and emotion. The second is that they already existed in some more active form as elemental spirits (so not as inert as Evelynn was prior to the Rune Wars for example) but mankind's stories came to give them a more definitive shape and form. I would generally trend towards the former interpretation.
Hope this helped.
is a goat/ram humanoid yeah?
is a bear humanoid....
, a straight up ice phoenix. I was wondering if she was a modern champion would she have also been a humanoid? Still an icy phoenix thing but shaped as a humanoid?
