A player trolled to make us "suffer". Then they threatened to shoot up a school
This was my first ever match of ranked on this game. This person was Nunu jungler and as soon as chat opened he started typing about how obnoxious trolls have been their past few games and what a shame it would be if there was one in this match. Right off the bat, they started roaming lanes and interrupting with laners. They thought we were deserving to suffer what they had been through their past games (as if somehow we were responsible for that) Both our and the opponent team were bummed out by his behavior and decided it'd be best if we surrender once this perosn started intentionally feeding the enemy players. We tried multiple times but he blocked the vote by roaming the map and ignoring it. When one of our teammates equated his logic of making us "suffer" to one of a school shooter, he got quiet and said something along the lines of "they should be careful. a storm is coming".
Regardless if it was a troll or not, this went from infuriating to disgusting real quick. Both teams took actions to report them, and I know sure as hell our team did. I don't know where I can follow up a report about this person or if the in-game report mechanic is enough, but I'm taking this very seriously and so do other players.
What are the correct measures to take now?