What is up with Garen's Page one LoL

So i went on today to read some of the lore and i decided to go over to Garen's, since he was the first champ. When i click to go to it a pop up sows up of Garen being shot through the chest and music playing. After that it closes and Garen's icon show him with his eyes closed and a crack in his face with crystals flying off. I was wondering does anyone know what this is or will this be explained in the future.