...does not work as it should. Whenever you use Pull on the Vicious Harpoon, it resets the cooldown on Drop Relic. I know that on the old client, you could Pull and Drop Relic as long as you had AP on your champ, and it wasn't your first turn with the Vicious Harpoon on the champion.
I don't know when it was done, but there's specific code to do this, so it's not a bug. The ability itself also reads: "Drop the Vicious Harpoon as a relic in an adjacent empty space. This ability shares a cooldown with Pull."
Great! Thanks for checking it out! I don't remember it working that way in the old client, but I have not used it in a long long time, so maybe it was changed long ago.