下面每句中的that起什么作用?

A guy who thinks he’s all that.作表语
What do you do with that power?形容词,作定语
Do you have anything that you need?作定语从句的引导词
And that was the goal,right?作主语
Do you have anything that you need?（上面有了）
补充：
表语是跟在 be 动词后面,起到说明主语是什么或是怎样的作用,跟宾语有些类似
定语是形容词,起到修饰名词的作用,如“火红的太阳”,其中“火红的”就是定语,修饰名词“太阳”