Terastodon, Woodfall Primus, and Primeval Titan are probably the best cards for the "big green creature" role, but Simic Sky Swallower and Broodmate Dragon can serve the role as well, although they require greater deck manipulation to be able to hard cast should you draw either of them before finding your Natural Order
Knowing you have no way to really win other than your 3/1 flying Vendilion Clique can be a scary thought
When its part of a spell or an activated ability, as with Sapphire Charm or Teferi, Master of Time, you can counter that spell or activated ability with a counter like Counterspell or Stifle
Dont miss that you can let one player kill an opponent and then cast this before moving to Second Main Phase to bounce their attackers
Ravnica block (2005) Ravnica updated the multicolored cards, by adding the hybrid concept: A card that could be red OR white, for example