Item description:

one last hurrah before the farewell.

go left and use the leyden jar to teleport. use laudanum just in case for stoic.

You gotta do the requirements to get each ending (which is good). pretty safe save. do it after your 1st playthrough. fake it till you make it.
Speedster, Stoic, Tasi, Provider, Harvester and Iconoclast

that's about it.

p.s. you might wanna get this done as soon as possible (if you have the game) as i have used a glitch to get that spare leyden jar all the way to this point. an update might fix it and i think i was short on time.