Ok, so this is the first GG I'll actually try to learn to play a bit more seriously. And I've found out that there's this long time eddie/zato player in my town. And I already hate the fact that hitboxes in GG don't hit two things at the same time. Also, how the hell do you approach Zato?
I'm going with Ky for now, he's the only one I somewhat understand. I also plan on learning Milia and maybe Ram/Elphelt later.
If he does a drill in pressure, it can often be a good idea to 2P because there is a good chance Eddie is coming, it is a risk though because he can throw a long poke out to catch you doing anything.
The key is keeping Eddie away, Zato on his own is still threatening though, he can effectively zone with his j.K, ground normals and drills.
You want to be on top of him because he has no reversal (he has Amorphous, but it doesn't hit just in front of him) and try to make him hurt. Alternatively, try to stay in the air and a good distance away from him, if you can get him to whiff something, you can approach fairly safely from this angle. If Eddie is available though, Nobiru will shut this down pretty hard.
Dealing with Zato + Eddie on top of you... it is tough, he is going to default to low strings, if he goes for the j.K > j.K or 2K mixup, well it is a guess but there aren't too many layers to that mixup other than command grab. I suggest saving your burst for when you are in the corner. Invariably any hit here will lead to unblockable. What you are looking for is a combo into 5D or a command grab, when they happen, burst, burst, burst. But don't be baited or you will be very sad indeed.
If Zato is pressuring you with Eddie out and the meter is running low, that is your queue to get in the air if you can because he is going to fish for command grab, he can't set up unblockables off a normal confirm with low Eddie meter.