One thing you can be sure, it’s not a regular PvE.
The start time coincides with noon EST (on Oct 8th), which is not the normal start time for slice 1.
So either another alliance coordination event, or Gauntlet style. My guess in either case would be with Galactus as the boss battle. No idea if the spoiler abilities sync with him in the comic universe, however, so he may/may not be the next 5* to boot
It would be REALLY cool if this anniversary pve turns out to be another alliance coordination event a la AVU. Also, I’m betting Mr. Fantastic will be the 4* essential.
730 item Vault. One item for each day of the game being out, with each item being a reward randomly selected from a reward you’ve received during your playtime. During testing, this resulted in average Vaults having 724/730 slots filled with 20 Iso and the other 6 slots being Crit Boosts, but we figure that’s a fair distribution of prizes given out to most players. /s