Another day in Champ Select!
On the boards, I saw a very informative way to punish champ select trolls here:
I took a screenshot and sent a support ticket and the picture to Riot Support. The game ended up in a remake, so my team wasn't harmed in any way. I couldn't report him though, because I reconnected a bit late.
Thanks, Real Sexy Yoona! I first thought it was too much effort, but I didn't want to waste playing a game with this troll. The ticket only took me 5 minutes, so if one of you faces this problem, I highly recommend it. I'm a hardstuck plat 5, so I didn't care about lp. If you guys have a problem with lp, dodge without waiting to see if this troll is bluffing or not and send Riot a support ticket! Don't forget the all important screenshot.