Can someone explain to me what good use is Diana presently?

Can she pop enemies?

Can she do well in group fights that involves an enemy with heavy CC such as

When can she engage/disengage without suffering the kamikaze syndrome that Talon used to have?

Is her strength early game or late game?

I have an issue in understanding what good use is Diana because she seems to be that type of champion who looks for an opening or opportunity to strike in but if fails, instant death comes along.