Titan EX latency.

[Anapingofness]

Ouch, yeah. I can see that getting annoying real fast.

If I may, have you tried lowering your settings? Limiting the effects of yourself or your party members?
Is your camera set to Legacy? Even a small amount of walking backwards can mean the difference between eating Landslide and avoiding it.
Unfortunately, Titan Ex is a merciless fight and one I think is in poor design but that's neither here nor there.

On the other hand...
Are you getting DC'd a lot? 90k'd?
Is someone at your home eating your bandwidth?
Is your router software up to date? Can your router handle your internet?

If you're like me, you don't really have a choice in changing your ISP.
http://www.speedtest.net/ use that to check your internet speed, if you aren't getting what you paid for make sure to call them.