do I really need to kill Paarthurnax to finish the entire main questline?

[Aco™]

Hello everyone! I killed Alduin and went back at the throat of the world where i saw a bunch of dragons, i decided to go to Arngenir and tell him that I wont kill Paarthurnax.
Did I finished the entire main questline or I need to kill the old dragon to get new quests?

[AC Denton]

Only if you side with the blades. If not it's over.

[Uncle64]

No you dont, there is one mod that fixes that issue.
Look for Paarthurnax issue made by Arthmoor.
Install that and load the save before you did your deciditon.

[liosalpha]

the blades and the greybeard have sidequest that are radiant when you pick a side.

Just like the heist missions form the thiefs guild or the brawl from the companions. they dont realy ad to the story of that guild/faction.

[Docsprock]

You can complete the main quest whether or not you kill Paarthurnax.

If you let him live, Esbern and Delphine will just mope around Sky Haven Temple the rest of the game and the Greybeards will tell you where to find word walls. If you kill him, the Greybeards throw you out of High Hrothgar, and you can build the Blades up to be a dragon killer team that will assist you upon request.

Using the mod that Uncle64 mentioned is the best route to take.

[Justice]

killing Paarthurnax isn't part of main quest and you can avoid starting it by quicky run away after the end of peace treaty meeting and disscusion about capturing dragon with jarl. Don't let for Delphine or Esbern come close to you to avoid speech script