While my process for 5-color decks is fairly similar (start with rares/bombs, add the best uncommons), I also start with adding all my fixing too
With an Ink cost of 3, 2 Strength, 3 Willpower and 1 Lore, Ursula doesnt look great at first glance
And hey, if you find yourself with more bulk than you can handle, remember that there are platforms, like Curacards, who would be happy to take it off your hands
If you don't want to cast it at that time (or you can't cast it, perhaps because there are no legal targets available), you won't be able to cast it later for the miracle cost
Even with its wacky name, it gives off the impression that the opponent is about to get a massive beatdown that is bound to hurt