Sweet. Time to put my time into playing Rondo of Blood on Wii's Virtual Console to the test with the original Vania.
When you face Death, get ready to throw your 3DS across the room.
Why? Death is easy. Triple Cross/Boomerang does the trick nicely.
Or if you really wanted to be cheap, Triple Holy Water him as soon as he appears and he will never move from that spot if you spam him with it.
Using the Triple Firebomb absolutely mauls him, and the Triple Boomerang also works quite nicely. But all it takes is getting killed on accident just once on the way to him, and your sub-weapon arsenal is gone.