Trinity force and Statikk Shiv will give you crit and attack speed ( 60% attack speed, 50% CRIT).
You start whit AD runes, masteries and a dorans blade that gives you some AD (trinity force also gives AD).
You'll have 2 CRIT items and 3 AP items whit full build. This can give you over 400 AP.

Having less burst damage is not the problem here I think.

What's the point in having AP and Crit together? Without the attack speed you aren't going to be getting as many critical auto attacks off and without any attack damage they won't hurt, and you're dealing less burst damage since the absence of one/two ability power items.

I know the AD Fizz builds. Whit mine, when you fall behind its hard to comeback. But saying you can build a blade of the ruind king would give a wrong idea.
Then your gonna be stuck whit both AD/AP.
What I could do is that their are other builds
wich do use AD.
My build focusses on AP whit a little CRIT.

There's a lot of room for improvement.

I personally dislike the build. Doesn't mean to say that it's bad entirely, but I do think that you should mention a potential Blade of the Ruined King rush against tanky champions into either a Trinity Force or Last Whisper. You also need to expand on what the abilities do. Your mastery/rune choices e.t.c.

Go more indepth of what makes Fizz a good champion with the Pro's and his weaknesses with the Con's. No champion is perfect.

I get your pint tho I can't entirely agree whit you.
2 Sheen is really bad. I don't even know how that came up in my mind.
When you say that this is the worst Fizz build you have seen? Hmmm, the AD runes you use to have more sustain in lane, farm and even out trade your lane opponent. You could use AP but I don't recommend doing that.
The AD part is a fault of me. Its should be AP/CRIT Fizz. I will change that.
Even tho it might sound weird, this is a really OP combination.
It does so much damage! Full AD doesn't work for me.
Its a very weird build, and I know that. But weird doesn't mean it had to be bad.
Also I'm far away from a professional player and I just tought that I maybe could give people some inspiration.
Tell me if I'm wrong and thanks for leaving a message. If you have any more problems make sure to say them!
I'll do my best to keep changing the guide until its good.

Not trying to be mean but this is the worst Fizz build I've ever seen. 2 sheen procks for some reason, your masteries are full AD even though you primarily build AP, no BORK. You should either be going full AD Bruiser or full AP, not both.

Trinity AND Lich bane? really? What division are you?