Which I cant imagine not being the case. Its all tricky I tells yah.
The game needs to be good as a video game. Every part of it need not necessarily translate straight to Lore canon. Experience points and the amount of normal/ranked matches that go on every day.. These dont seem to fit with the story. In a weeks time every single champ is probably paired with every other champ on some team, and a thousand summoners gain more power. Power would be meaningless, all political affairs would be resolved, clones wouldnt benefit the champs..

Some elements of fights certainly Are canon, such as the purchase of items. Ezreal donated Wriggle's Lantern and the Institute began preparing replicas for League purposes, as written in the first JoJ. The earning of Influence is another example, but one perhaps more relevant.

It is written that the Institute does have a bit of hierarchy. There are departments reminiscent of academia stated to reside within, and we have the lines "The League of Justice is supervised by a council of three powerful summoners, known as the High Council of Equity. Each summoner has been on the Council of Equity since the inception of the League of Legends except for its newest High Councilor, Heywan Relivash; High Councilor Relivash’s ascension took place five years ago after the mysterious disappearance of the previous High Councilor, Reginald Ashram. The Council of Equity is responsible not only for the leadership and guidance of the League, but also to act as the highest court of appeal for adjudication of Valoran’s political entities.
The structure of the League is focused around internal organizations that lead their various goals. Each city-state is assigned an Emissary of the League – a diplomat who serves as an on-location political representative to enact the will of the League. The Adjudicators are the arbiters assigned to a given match in the Fields of Justice. The Council is the body of high-ranking summoners which rules over political outcomes once a battle arena match has been resolved."
If there is a High Councilor, there must be a manner of selecting a High Councilor, and there must be a power ladder for him to sit at the top of.

In general, I get the impression that the majority of summoners are simply Mages. People who are very learned about magic (or a specific branch thereof) and work toward their own purposes in private organizations under the rulings of the Institute of War to assure that their affairs are systematic and do not further damage Runeterra.
To that end, I would say Influence is the only useful measure of summoner rank. As one rises in prowess and notoriety, ones organizational interests are furthered and ones resources expand, not much differently from how its done in reality.

This is why I wouldnt wish to see Champions have their individuality stripped, lowering them to the status of replicated Wriggle's Lanterns. It invalidates the significance of Influence, and it saps the stories that would come of making pacts with a Champion.

With these ideas, A very influential Noxian Summoner for example would be someone who learned magic from a college such as the Bleak Academy, became noteworthy, attained station with noxian political interests at heart. Some issue would then occur that was due fighting over (Perhaps he got in a quarrel with a Demacian summoner and this is a duel of pride, or perhaps its a highly official contest over a piece of land, or perhaps the Noxian has been tied to some Demacian crime and rather than the shortsighted all out wars of the past we shall now decide justice on the fields thereof) and the Summoner was thereby introduced to a Noxian champion.
The champ might agree to the be the summoner's weapon for payment, or due to the Summoner's standing in the city, or even because they are of like mind and wish to wave them Noxus banners high. A number of champ lores speak of seeking to be a Champion for any of these causes and often indicate the Champ does gain something for his services.


The OP questioned the 'where'. We have the line: "Sealing himself inside the easternmost summoning chamber, he began incanting the most forbidden of rituals - an extra-planar summoning."

Here we see that the Institute dedicates particular chambers to the high magic of the summoners, and also have an one example of Summoning without pacting but one I feel doesnt indicate Noxians can summon up meat puppet Garen whenever they please because Fiddlesticks is rather a special case and visiting that chamber is now instant death. Consider, instead, Anivia and Malphite, who were summoned and then -agreed- to fight, or Morgana who was paid great magics in exchange for her service. All examples of Influence; The right people with the right resources.

Thus, my thoughts on the Magic of summoning are that while there is obviously a connection between Summoner and Champion being sustained by powerful magics to the benefit of both, It is still the Champion proper, full of his individuality and personal prowess and spoke of throughout the lore as though a singular entity.

The mental link serves the Champion by making him more than some chap on a field. He gains vast awareness and a connection to his allies. It serves the Summoner by giving him a league-approved weapon of great capability and esteem.

The Summoner can use various powers to bolster the champion beyond his ordinary capacities, indicating an interesting way of ranging his spells through the link, and can whisk his champions form back to the Nexus for repairs. Imagine what it must mean to be a Champion, then.. To come so close to death with every cause you chose to fight for. Youre volunteering to be tortured in a thousand creative ways, only to be patched back up to do it again. Not everyone is up to it, and neither is just Anyone worth doing it for.