Well, Finn is suppose to never discard items... well, what about the tomes ?

Can he read several times Cabala_of_Saboth and win a skill each turn ?

thank you for your lights

I think the consensus is that if the discard is part of the cost of using an item, if you want to use it, you gotta discard it. So Tomes, Flute, Dynamite, etc. aren't infinitely reusable by Finn.

Great. That makes sense to me. Thank you,

It's the difference between "must discard," which Finn is immune to, and "must choose to discard," which he isn't.