Is it REALLY evil???

[Tanarii]

My opinion*:
By 5e Alignments, this player absolutely should have select the Chaotic Evil Alignment for the PC. Chaotic Evil's typical behavior is "act[s] with arbitrary violence, spurred on by their greed, hatred or bloodlust."

This character is clearly arbritrarily violent and spurred on by their bloodlust.

Note that why the PC does it isn't important to 5e Alignment. PC intent is irrelevant. What matters is the Player using it as a motivation to correctly represent the appropriate in-game behavior they want to represent. In other words, it's objective from the players point of view of "I want to play a character that murders creatures violently, specifically in a manner that is arbitrary and bloodthirsty", not the PC's "but it's so I can eat them afterwards".

If this player wants to represent a bloodthirsty and arbritrarily violent Orc PC, and clearly they do, then the appropriate Alignment to select Chaotic Evil for their Alignment. IMO if they selected anything else they didn't review the 5e Alignments and select the one that fits the persona they wanted to represent in-game.

*Its my opinion because Alignment behaviors are left open to the player, possibly with DM recommendations based on what's appropriate for their game, as to what 'arbritrarily violence' and 'hatred, greed and bloodlust' mean. But I'm hard pressed to see how indiscriminately slaughtering as he sees fit, including civilians and children, is anything else. That's doing it arbritrarily and bloodlust-ily as far as I am concerned.

(Edit: it'd be a totally different matter if it were a Human Barbarian slaughtering Orc children of course. That's saving the world. )