Alucard at the end of the series becomes omnipresent and truly immortal. Having two souls within him, his own and Schrodinger's, he is completely the most powerful character in the series.
Ability to be everywhere and nowhere at the same time at any time
Can control and manipulate physics at the quantum level
Heightened Regeneration powers
Ability to be nothingness or enter a "void" in which Alucard is not present anywhere but is "not dead or alive".
Ability to return after having his existence eradicated