You teleport to Syb's house where his sister keeps all the boxes and jump onto the desk and then pull out the echidna quills. There were many items found in the Suki box, of course, we know that that box was supposed to be given to Syb. A lot of the items are weapons, as mentioned, the flintlocks of Zillyhau, but we also now know that the Echidna quills will be found in the box. What do the quills of echidna do? Scratching. Catscratching. You didn't find out until the last minutes of the game that the box was supposed to be for Syb. He just kept it out just in case she made it, but once you saw that the last player on earth entered the medium, it was over, and you all opened it.
In it, there was a note for you, that you were supposed to take these quills back in time when you went. You don't know why it was there, maybe it knew that this timeline would exist, or something like that. You head those words, and complete the delivery. You now jump into the box labeled for you and wait there to die.