A simple stroll with the Magical Cat is providing champions with unintended power.
The newly-reworked Yuumi has only been available to play on live League of Legends servers for a little over a day, and shes already wreaking havoc on Summoners Rift thanks to a new bug leading to an unintended, powerful interaction.
Players have found that, if Yuumi attaches and detaches to an ally that has a Tear of the Goddess in their inventory, each time she does so that player will gain a stack of the itemallowing the ally to essentially gain power without doing anything.
Thankfully, Riot Games has already acknowledged this exploit and is looking into a fix, though the champion has not been disabled yet.
While most champions do not normally buy a Tear of the Goddess as their first item heading into lane, AD carries like Ezreal and Varus, as well as various mages, can opt for the item early to stack towards a completed Muramana or Seraphs Embrace as a first or second item. Both of these legendary-tier items, when fully completed into these final forms, give champions substantial extra damage based on the mana they have.
A screenshot of this bug occurring in-game uses a Yuumi player to provide their ally Ezreal with nearly 45 stacks of Tear of the Goddess before they even get into lane, allowing Ezreal to deal more damage consistently with more mana. And, thanks to the changes accompanying Yuumis rework, she can provide an ample amount of survivability to that empowered Ezreal, making them nearly impossible to maneuver against in lane without outside help.
It is unclear when Riot will be stepping in to fix this bug, though it is likely to be hotfixed relatively quickly. There is also currently no indication as to if Riot will punish those that use the bug to their advantage in any League modes.