"You are immune to all explosion damage" - except not?

[bendor_berlin]

So I unlocked the Popcorn and when I go to the Inventory screen under the Popcorn Item description there is a green header saying "Will of steel" and beneath that it says "You are immune to all explosion damage." ... Except I'm not? Explosions still very much hurt me. Is this a bug or is there something I'm missing? Has this something to do with the 4 grenade icons displayed underneath all that, only one of which is lit?

[InstableMonster]

isn't that a set effect that requires multiple piece of the set to take effect? if i recall correctly each green grenade is an item of this set you have, when you have all grenades green then you get the set effect

[Taylin Sora]

in order for this to be active you require enough explosive type passives to be on you all at once for it to activate, after that 0 explosions, yours or enemy or environmental hurt you, which is different from "big daddy" which gives you only self explosion immunity