Effects setting Angel’s Tomb’s base power and toughness to specific values that begin to apply after Angel’s Tomb has become a creature will override the effect of Angel’s Tomb. For example, if an effect causes a 3/3 Angel’s Tomb to become 0/1, it will remain 0/1 until another effect (such as triggering the ability of Angel’s Tomb a second time or targeting it with Titanic Growth) causes those values to change.