The Death of Imagination

I think "letztendlich" is rather different -- more like "at the end" or "when all has been said and done". As in, "Letztendlich läuft das auf dasselbe hinaus" (it all amounts to the same thing in the end) or "Letztendlich kannst du eh nichts dagegen tun" (You can't do anything against it anyway).

"Endlich" is fine.