Playing a brawl match against someone using Oko, the Ring Leader as their commander. The issue arose whenever he started using the ability: -5, For each other nonland permanent you control, create a token that's a copy of that permanent. That's fine, whatever. However, they also had cards that gave them extra turns. During each of these (in total five turns), they kept using the ability mentioned above. Now, my hardware far exceeds the recommended specs for MTG Arena, but when you double all nonland permanents over and over, the game lags. So much so that I had to end the process and start it up again just to get it working again. And with the five or so extra turns they had they kept me essentially *******, forcing me to walk away from my computer for around 20 minutes as I would just load into their match again and crash. Maybe it's an exploit, maybe it's just a get better hardware issue, I don't know. I just thought I should share it.