So, the game I just played.
Opponent bought a Death Cart for some reason. He wasn't doing anything clever with it.
He promptly collides the Cart with a Ruin, and then spends his $8 on a Prince.
So now his deck has a Death Cart, a Ruin... and a Prince.
But! He then gets an Oracle.
And then collides the Oracle with the Prince the first time he draws them.
I had a strong suspicion this meant the game was over, but I kept playing anyway.
I got my own Prince and Oracle later on, after I trash down.
They proceed to spend most of the game avoiding each other.
Eventually I do collide them, and get a Province and a Duchy... while he already has 4 Provinces.
The cherry on top was right after this when I discarded 2 Silvers with my Princed Oracle... and instead draw the Province and the Duchy.