I just got this drop from the chest after defeating Red Skull. Got a bts, sinister unique (always wanted one for Loki), ult token (used it for Cap), lvl80 Mkraan Crystal, Thor dupe and Captain Marvel costume. Probably used up all my luck for the rest of the year. LOL
Edit:
Just found a 2nd one. This time I was able to hold it back from picking it up immediately and walk away from it to check the screen indicator. There it is. Also gratz to my SG members @Scorponok & @MindTricked who found a scroll each together with me within half an hour!
