Well, that was quick...
It seems the speed of Rakan's Grand Entrance somewhat found it's way to one of the shortest-lived metas in league: Frostmancy.
What the meta was about, was using a ranged, spell-spamming champion (Karma, Zilean, Zoe, etc), buying Spellthief's Edge as your first item, and partnering it with the Kleptomancy rune.
Up until you complete the Tribute quest of Spellthief, you only have one goal: poke the enemy and do not take any CS.
Sounds weird at first, but with how KingZone Dragon X utilized the strategy against SKT during their first game last Feb. 13, it's effectiveness cannot be denied. To be able to literally light up the map and locate your enemies and see them come from literally a mile away, might be not as useful in Solo Queue, but in the Pro-Scene, it decides the whole game.
What Riot intended for map vision (since removing Stalker's Blade), is for players to learn "smart" and "controlled" vision. Frostmancy just happened to be a loophole that has just recently been found.
In any case, Riot has already implemented a hotfix which requires an ally to be 1500 units in proximity of a Spellthief user to activate the Tribute effect, which effectively kills the meta, for solo laners that is. Bot duo laners can still make use of this, most notably Ezreal, but it will be a decision between more vision control and an item slot for offensive or defensive items.
So long, Frostmancy. May you be remembered as League's quickest meta.