Lore Trends by Champ Releases
2009: The Original Crew
All champions at this point were billed as entities summoned "from other worlds" to fight for the League. As yet, the major factions such as Noxus, Demacia and Ionia were outside players, and Riot was very much throwing things at the wall until they stuck. The foundations for Freljord, Shurima and Ionia were laid down, as well as Teemo and Tristiana, who were at the time different races (yordles and meglings). Much of the canon from this era has been ret-conned, with champions taken from their own unique odd little settings and fitted into their modern canon slots (like Karthus migrating from the howling marsh to the shadow isles). The concept of summoning from other worlds was quickly retconned and today very few champions reflect that lore, the clearest being Morgana and Kayle who have not been integrated into Valoran
2010: The High Era of Politics
The lore really got into swing with the introduction of the various faction crews. Each champion released was tied carefully into existing champion factions, and we got many Demacian, Noxian, and Ionian champs. Poly over and Zaun were somewhat expanded and a clear cut factional theme took hold. This combined with the cohesiveness of the Institute of Lore makes this era the high point of the game for many when it comes to storytelling.
2011: The Drying Well
The limitation of the factional setting turned out to be the lack of truly interesting character types available. Woman/Man with weapon/magic can only carry so far, and it's around here we see the fall of Leagues cohesive Lore around about Riven. When we've got the head of Noxis and the prince of Demacia fighting, where else do you go? At this point, LoLs designers cared more about characters they wanted to make than fitting characters into the factional categories. They hadn't made an oddball like Rammus or Amumu in a long time, so the pendulum swung towards the modern era of League's lore, and if 2010-11 was the High Age, this was surely the Dark Age.
2012: Detroit Trope City
Almost every character in this region becomes a one-off, generally following a well known character trope to make them attractive and interesting "at a glance". To find Xin Zhao interesting, a player must first care about the Noxus/Demaci conflict and it's relationship to Ionia. To find Rengar interesting, a player must only recognize that he's meant to be a knockoff Predator-his only character is a takeoff of that pop culture character, as it Khazix's. Characters like Volibear, Nami, Fizz, Ziggs are released only because League didn't have a character like them and individually they were judged more interesting than the Karma's and Swains of the previous eras. Occasional faction champs were released, but few and far between and usually they weren't tied in with the others as they had been
2013-14: The Slowdown and the Era of Dissolution
Champ releases reaaaally start to slim out 2013-present. The lore is either near-nonexistent or is started but never finished, like Lissandras Freljord conflict. The cohesive Institute storyline with the players as summoners is not ever added to, and all references to that are removed from in game wherever possible. Reworked champions' lore is fragmented to remove them from that narrative and from the "tacked on" character interaction they had before.
2014: the death of the Bio Paragraph
Lore is reduced from a short bio paragraph explaining a character's motivation and backstory to short, ~500 word fan fiction style stories. Old champions who are reworked receive the same treatment such as Twitch and Karthus, and most new characters are just a picture and a few words about This One Thing They Did One Time, in the style of the older champs with the weakest lore (IE Mordekaiser). Lore is, at this point, completely dead.
