How do you trim a cut out?

Can someone tell me what type of trim and how to trim this area? I've got regular drip edge tacked up there for now as you can see.

If I put a rake trim up then water will smack directly into it, and I can see that leaking at some time.

I'm searching all over and can't find anything on this.

Thanks all.

Here is a modified pic

This is the style of rake trim I have everywhere else... you can see how that will be a problem even when you cut and bend the ends down to try and box it in at the ends.

I was also thinking of getting just regular flashing, bending a 90, then using a load of butyl tape and screws. But with all that water rushing down and smacking into it over the years, I dont know if it will hold up.

Pic didnt post... here it is again: