Cheat Mode and Invincibility:
Quickly press Block, Auto Face, Dark Gift Menu, First Person Look, Action, Use Dark Gift, Suck Blood on the main menu. A voice saying, "Go Cheese" will confirm the code. You will have the Soul Reaver and Iron Armor when you start a new game.

NOTE: The next procedure involves editing a game file, so create a backup copy of the file before proceeding.

Use a text editor to edit the "game.erg" file in the "Data" folder inside your Blood Omen directory. Remove the hyphen "-" character from the line:

"-bo2 kain debug flags\kain's invulnerable"=1

The editted line should appear as:
"bo2 kain debug flags\kain's invulnerable"=1