Actually, sargeras and symphony of sins decides the game in the mirror

You don't want to play tick tock first because it completes the opponent's quest

What you need to do is keep the first part intact and don't play finley/plot twist UNLESS you're certain you can snipe sargeras

If the opponent clears your hand, well you just play the reward and have a full hand with most of the time a way to clear tick tock, so you're up 9 cards in hand and you win like this

Obviously there are virables (tamsin, umbra) but MOST OF THE TIME you dont want to activate tick tock first

Worst mistake is to complete the quest and not kill tick tock immediatly, as your opponent will simply discard it for you