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
Wojek Investigator Card advantage in white often comes with conditions, and Wojek Investigator delivers it cleanly
This kind of buff turns a lot of Commanders into a one-hit knockout, including the likes of Ghalta, who makes it free all by herself
A+ Dimir Charm While there wont always be a sorcery and the mill is a little sketchy, the Dimir Charm should generally be able to find a target to take out with the creature removal option
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