They changed it but I used to use /assist Xzin and then /cast then TargetLastTarget();.

Now they changed it to be /targetlasttarget. Same basic functionality but it is protected code so harder to manipulate from an API perspective.

I am looking to try focus as I will be able to modify the focus on the fly (like when my main character dies). My new setup is changing the focus from being Xzin centric to being able to be controlled by any character.