why are elites trying to kill chief
Well, not all Elites like the Humans…
Besides they may have been trapped on Requiem and unaware of some sort of peace between the two species…
Some Elites want to kill all humans, not all the the Elites sided with Arby.
It could also be a group of rogue elites and heretics like in Halo 2.
And what OnyxTech said. Not all Elites agree with Arbiter. The ones against him may take over control in the next 2 books. We don’t know for sure yet.
(=