All Legendaries and Epics (Except Colossus)
I haven't seen that before but based on the message it only lasts 3 seconds, then you can run it, if not I suggest you use the link in game for Live Support / Chat.
I have seen this setup few times, and i have no idea how to beat it, especially since Fox is only good hero which can hit them while being elusive. I tried many times until i decided to skip this configuration every time it will show up. I know this is not what You wanted to hear, but i am not sure if anyone can beat it.
From what Ive seen a team of pd, fox, zeph, trixie/gs, dove, and walla/occult/ram can beat this dungeons. You need fiery comet as a insig/tal on 3/6th or more of the said heros and sunder on trixie/gs, dove and zeph.