Abandon the Lib-Con ping pong game.
Two heads of the same corrupt monster.
Vote for something that matters.
You're assuming any other party that wins will be any different. The Greens or anyone else would be corrupted with power like any other party.
Your argument is admirable, but IMO unrealistic. At best the Greens swap places with the NDP and become official opposition, but that would mean splitting votes with the Liberals and giving the election to the CPC.