We don't talk about Pun-Pun
I went to a convention to play an EPIC once (CODCON at the College of DuPage). Miserable experience, lol. They had different tables for different level bands, all technically on the same adventure but different areas. The high level table had to deal with flying enemies. If they failed to stop them all (and they did, every turn), the lower level table got an aerial bombardment, announced by laughing and joyful screams of "Death from Above!".Epic level play in 4E was an interesting experiment, but it was very difficult to set up appropriate challenges. Player's capabilities to shut down or bypass challenges altogether abounded. I played in the LFR (the public play for 4E) campaign that went to 30th and one of the biggest complaints was that the modules constantly came up with some fabricated reason we couldn't use our powers. Especially the first few modules in the series were "Ha ha! You can't use all those toys you've worked so hard to get!"
It took me a while to figure out how to handle it for my home campaign and I'm not sure I ever really succeeded. Battlefield control, totally nerfing the opponent, was just built in to the DNA of 4E. When the PCs did it, games became boring because there was no real challenge. When the monsters did it it was boring because players had no choice but to sit and wait. Still can be an issue in 5E of course, and about the only solos I've found that work are creatures like dragons that can fly out of sight on their turn (which can have it's own frustrations) but for me it's been easier to find the right balance. Of course I get to stop at level 20 now and that helps as well.
We survived by dearth of being stubborn, and got some big useless quest rewards, but in the end I didn't feel like I'd participated much. Add to that the DM who didn't understand how my Knight's aura worked, or badly communicating what we were meant to do.
We were in this tunnel at one point full of monsters. I said to the DM "are we meant to fight all of these?". "No, you just need to get to the end of the map in X amount of turns" I think we were delivering a message or something.
"Right, ok. I use my bonus action teleport from my slave tattoo (thanks CALI), run, action point run, and now I'm over here."
"Uh, ok, you escape."
"So we win? No, you all have to make it."
"...that's not what you said, can I go back?"
"No, you're done."
I sat and watched my allies flail about for another half an hour and die. Then get told we failed the adventure. One of the other players went on the same CALI adventure and had a tattoo they could have used to teleport to me....except I was "off the map".
Fun times, lol.