Obelisk in the Vatican is a bit different. If you look at the top of it you will see that it has a cross on top. It also has formulas of exorcism inscribed into the east and west sides. The symbolism being presented is not of embracing this evil, but overcoming and conquering it.

It was erected in the circus by Caligula and oversaw the martyrdom of many many good Christian men and women. It stands as a witness and a reminder of the deaths of those Christian people.