Which tool/items obtained through a quest are useful in a non-related content?

Question

There are many items obtained through quest, some of them remain in our bp (ghostsilver lantern, molten wax, tool for analyzing fluids, etc) other are obtainable again (holy water, medusa ointment, etc) but are items that can't be obtained through other methods so in order to obtain them we must progress in these quest so only once progressing in these quest we could maybe progress in another quest, or get an achievement or discover something that at first sight seems not directly related, thats why:

I want a list of items obtainable only through quest that can be used in content that isn't directly connected but still such item is needed/useful to progress in this other content (achievements aside the obtained through quest, other quests non directly related, other content as being directly involved to solve a mystery, even items that could trigger a "event" non directly related with their main quest and with unknown usefulness)

Answer 1

Ritual scissors which are obtained during the Kilmaresh quest can be used to sheer sheep for wool.

Comments

that's cool you could obtain an achievement with these? any other item?

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Im not agree with this answer at all,

You will need use this scissors to take some items to give it into the quest.

I mean, this item is usefull during the quest

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The idea of the question is to list items that are useful for a non-related content, yes, say using the molten wax to solve the crystal garden quest which provides an item (flask of medusa) which later could be used to pass through a door on dream labyrinth.

So if the item has no use than progressing in their main quest (where it was obtained) isn't enough, indeed.