Hey man nice team you have here!
Looking at your Magnezone i understand it's job is to trap Ferrothorn but it doesn't seem to be able to do that much apart from that. Infact i would go so far as to say it slows down the offensive nature of your team because of its inability to be fast enough to dish out real damage to anything but Steel-Types with a 4x weakness to Fire. Offensive Ground-Type pokemon can switch in and cause havoc like Swords Dance Gliscor. This forces you to switch which isn't exactly ideal on pokemon like Choice Band Landorus-T who can hit your switch in hard with Stab Earthqauke or just U-Turn out. Speaking of Therians Thunderous-T looks pretty dangerous against Magnezone as well especially the Agility set which can easily get an Agility on Magnezone and sweep your team with a combination of Thunder, Hidden Power [Ice], and Focus Blast. What i am trying to say is that Magnezone opens your team up to alot of offensive threats when it is on the field due to its poor coverage and feeble Hidden Power [Fire] in rain. Even though it's supposed to take on Ferrothorn with Hidden Power [Fire] being a 3hko at best Ferrothorn gets the time to set its hazards up. Thats why a good change would be Terrakion>Magnezone Terrakion is a great offensive pokemon and an awesome revenge killer to have in your team. He wrecks nothing synergy wise as he posses a rock resist like Magnezone and shares alot of the same weakneses with him. Terrakion can also deal with Ferrothorn using Close Combat. Althoug he cant directly switch in due to your team having a sturdy Volt-Turn core in Landorus-T and Rotom-W Terrakion can often switch in because Rotom-W lures in Ferrothorn. Also alot of the times Ferrothorn will go for Spikes giving you a free switch into him. Terrakion is also a good pokemon to use against Tyranitar a rival weather abuser who will not want to switch in to much because some of your members can simply Volt Switch or U-Turn into Terrakion. This helps you with the weather war which is good seeing as this is one of those rain teams without Dugtrio.
Another thing i noticed about your team was that nothing really wants to take a Hurricane from Spec Tornadus-T except maybe Rotom-W who will get destroyed by it's Grass Knot. Speaking about Rotom-W it has more then 510 evs haha, but if you decide to go with my change of Terrakion then you can very easily run a Specially Defensive Set>Choice Scarf Set Specially Defensive Rotom-W is one of the best checks to Tornadus-T and also provides your team with a bulky pivot which is great because this team hasn't got to much pokemon to sponge powerful water type attacks from rival rain offense teams. This set still keeps it's Volt Switch and Hydro Pump but can also utilise Will-o-Wisp to it's advantage burning common switch ins and giving Haxorus an easier time setting up. Rotom-W also helps your team a little more against Genesect as he can take his attacks quite easily.
Other then that great team i hope i helped :)