About the T2 Alpha Catalysts.
I have 8 Tier 2 alpha catalysts. Will it expire if i have one in the stash? I don't have any good 5 star hero to rank up, but I want to clear act 5 chapter 4, but then I'll have one catalyst in the stash and that is the only thing keeping me from an initial clear. It would be a great help if they didn't expire though.