Other cards to consider are Bearer of the Heavens(if you're feeling really spiteful), Burning Anger and Toralf, God of Fury Flip
If your opponent casts a bigger creature, you cant steal it, so your options are a little worse and you might need to rely on your following spell to answer it, but if your following spell is a Wicked Wolf, for example, no matter what they cast, you could turn it into a 3/3 and then use the Food you created the previous turn with Oko to kill their creature with your Wolf after making it a 4/4
When the dork arrives you can target it with a spell to exile the top card and cast it
However, its hard to overlook how much this overlaps with the Doctor Who energy deck from last year
This deck runs a lot of bizarre cards, and they can all target your own permanents so Orvar can copy them