RENMX | Forum

can a player build a building within 100 blocks of a diagonal line of another build and then claim there build, putting the 1st build within the 100 block rule?.

you've confused me. so they are building 99 blocks away from a build, then claiming the build they are building 99 blocks away from?

BY looking at the situation the player building (who shal not be named) isn't actually braking any rules. referencing to Pri's official set of rules for the server;

Don't claim land within 100 blocks of another town/outpost without permission.

Unfortunately because your ender farm isn't part of a town or an outpost according to the rules he isn't doing anything to brake them.