There are likely a number of dragons that were of similar relative strength to Rith, the Awakener over the years, but Rith, the Awakener got its moment while those others did not
That chosen companion doesn't start in your main deck
In their eternal search for perfection, called 'compleation' (yes, spelled like that), a process that fully replaces a beings body with metal, the Phyrexians have produced monstrosities and abominable machines to further their progress
Flying threats can also exploit Fields flaws, though they do have to slip between Shatter the Sky and various Planeswalkers to get there
If you dont get shut down in the early game, you have a lot of removals and can use cards from your graveyard, but as I said earlier, you need to play carefully