>>211696936
>why would sheev spend all those years training maul to the point of him getting a sith title just for him to be disposable?

Because he realized Anakin had 100x the potential of Maul.

Also a core aspect of Sith ideology is their not placing value on individual life or loyalty. Hence why whenever the Sith try to run any form of galactic government, it spirals into backstabbing and bloody power struggles.