Hi. Nice team. Hail is definitely a fun weather.
One of my first main issues with the team is, what are you using hail for? You have literally like two ice type attacks on the team, not even a Blizzard, just Ice Shard and HP Ice. You might consider replacing a Pokemon or adding Blizzard to a Pokemon or two (Tentacruel, maybe?)
As it seems that you are using hail simply for residual damage, I like the use of Tentacruel's TS and Sableye as your spin blocker. He's one of my favorite Pokemon. However, as residual damage is what you seem to want to do, that becomes much harder against fire types (no WoW burn) and a team that has even just a single Poison type or rapid spinner. Then you are left with something like four Pokemon who have some easily exploitable 4x weaknesses, and it all goes to crap.
I see that you use Virizion as a pseudo rain check, Landorus as a pseudo sand check, and Heatran as a better than pseudo fire check, but I think one or two of them need to be replaced with Ice Pokemon, or just other Pokemon that aren't so 4x weak. You might consider Snow Cloak Mamoswine to replace Landorus. Kyurem can be decent, especially with spin support. Froslass can be used for Snow Cloak and Sub+Disable as well, adding an extra layer of annoyance to residual damage + Sableye. I would probably keep Virizion, though, as Work Up is great on it.
I love GoT, so I like the theme. Hopefully your team works well for you and other people can help you improve it! Because I'm certainly no expert at Pokemon nor at hail teams. :P