Invisible champions

TL;DR: 2 enemy champions were COMPLETELY INVISIBLE.

I entered a normal blind pick game, pressed TAB and there were ONLY 3 CHAMPIONS on the enemy team. I thought, eh, visual bug, they will show up later. Went bot, played as normal. Suddenly, i got marked with a Lee Sin Q, then E, then dead. NO LEE SIN AROUND. I could see his spell effects on me, but no skillshots flying towards me or anything.

Until the end of the game, i still couldn't tell who their jungler was. Only that i saw a lone little wolf following...air, so he had devourer.

RIOT, I THINK THIS IS A LITTLE MORE IMPORTANT THAN THE FACT THAT THE NEW CHAMPION SELECT IS NOT WORKING PROPERLY. FIX THIS ASAP, IT MAKES THE GAME COMPLETELY UNPLAYABLE.