Why event boosts are deleted after events?
They are not deleted. They are invisible until the event runs again. If you have a Thick as Thieves boost left over at the end, it will be there when they run it again later in the year.
Small consolation, but the state of affairs as it currently stands.
I had 4 tokens from previous event, and I kinda expected them to be available in Thick As Thieves.
They do say they are specific to that event. “Heroic Mode” only and such…
Only that they’re for heroic mode, not that they’re for particular event.
The event boosts says like ‘For Simulator only’ or "For Prodigal Sun only’ and so on.
“Heroic mode” are any of the events titled “Heroic: [insert prologue/story chapter name here]”. These are harder versions of the prologue/story chapters, where they limit your total usuable heroes to like 7 or 8 total. Recent ones being Heroic: Oscorp, Heroic: Venom, and Heroic: Dark Avengers (iirc). We’ll probably have another one in another week or two the way things have been cycling around lately, so your boosts will be usable there. I never really know when you should want to use one, so I just never do and they just sit there forever.
I used them on Heroic Venom because you don’t have Magneto to bail you out there. They’re actually quite useful because they stack up to 3 and getting +150% ability damage lets you beat even the level 395 stuff. However the risky of accidentally buying 5 more at 500 HP is too scary so I stopped using them at all.
I kinda expected Heroic boosts to be available in any Heroic event instead of being for 1 particular.
They are, but things like Isotope 8 Brotherhood aren’t heroic events. It’s Episode 4.