You have a Magnezone. I now like you more than I did before I saw this RMT. I also love the fact that you're using HP fighting Fat Lati; I thought I was the only one. I'd still run Draco just to do something to the usual things that Kati can check, however. Like, you can't really switch in to Keldeo well with anything else without risking a big chunk or a burn, so may as well replace Toxic for it in my frank opinion. I get that you like poisoning things like Chomp and Lando-T and Rotom and Hippo and shit that switches it, but most of 'em take a massive amount from even a weak Draco anyhow. Or maybe you can run Thunderbolt just to exclusively deal with Keldeo and Torn-T better; Fat Lati can tank whatever Torn-T normally throws at it, even a Knock Off: 0- Atk Tornadus-T Knock Off (97.5 BP) vs. 252 HP / 152+ Def Latias: 106-126 (29.1 - 34.6%) tickles. Granted, Hurricane can still do its shenanigans, and LO Torn can wreck you, but something's better than nothing, what?
Now, as for the Gyarados issue I don't see what the issue even is, but maybe running HP Electric or Taunt on Keldeo can work to arrest a sweep. LO taunt works well for me versus those ugly fat things that like to do ugly stuff as well. That's the best I can come up with now, hope I helped.
And yeah Volcanion needs to go.