Dark smog, Darkflare Dragon and Tour Bus has one thing in common. They all are the begining of what is coming. A extreme control environment, where everyone will be trying to create a graveyard and stop the opponent to create one for him.
All the meta decks need to control the grave more than before:
1: 4 fairies
3: Inzektor Hornet
4: Bulb + Spore
5: Dark + Light
Tour bus accomplish two things, fits the hole that Sangan will left when he have gone, and you can send it to the grave with eclipse wyvern to bring back lightpulsar dragon from the grave.
Tour bus will be the next grave control card on the game. But this time is way better that his predecessors because the target will be back to the deck, instead of being removed. So, leviair won't safe you from that.
I mention leviair because rank 3 have become the most important rank on the game, just like lv6 syncro was when brionac and goyo were alive.