Encountered a CHEATER in Ranked MM in DE, how to report?

As title says. Played vs this guy in Ranked ladder BF game just now, the way he played felt like a total noob so I was not really playing serious and just experimented with some builds. He clicked up to FC in 12 mins, with not taking a single boar and towards end of the game he spammed me with GENGHIS KHAN HERO UNIT. Like wtf?

I went through the replay, turns out hes a noob just getting tributes from gaia the whole game and can create hero units IN A RANKED GAME???

Please advise on how I can report him, as I did not see any option to do so. I have the rec if anybody wants to see this bullshit.

So mad that I cant even play a ranked game in peace now.