Targeting previous target

Focus lets you set a special unit as your focus and then direct abilities at it programmatically. Basically I want to always keep an eye on this and do thing to it.

Mouseover lets you put you cursor over a unit and then cast on it.

For CC I’d recommend a focus macro:

They can also be much simpler than that

#showtooltip
/cast [@focus,harm,nodead] [] SPELL