Hi kidogo, long time no see :] I was going to say that Tornadus-T could probably pull a similar job to your Tornadus right here, but I definitely see the appeal of prankster substitute as I have abused them before Thundurus' ban. In addition, pairing up subprankster Tornadus with Gastrodon is an amazing idea because of their great synergy, and choiced users would often overpredict thinking you would switch to Gastrodon to sponge whatever supereffective hit they're throwing at you, while your prediction is essentially risk-free with prankster subs. I would definitely have to try out that combination sometime.
Although I haven't faced this team nor have I used it, I see how effective it can be. My only concern is your matchup vs sun teams, as Ninetales can freely spread burns around your team and Latios will be quickly weakened before you know it. Using scarf Latios as a revenge killer also has the disadvantage of being easily trapped by Ttar, and that could pave the way for opposing boosting sweepers to power through your team. These can all be played around, of course, as I doubt you have any replaceable member on the team.
At any rate, great job, and congrats on the peak!
Although I haven't faced this team nor have I used it, I see how effective it can be. My only concern is your matchup vs sun teams, as Ninetales can freely spread burns around your team and Latios will be quickly weakened before you know it. Using scarf Latios as a revenge killer also has the disadvantage of being easily trapped by Ttar, and that could pave the way for opposing boosting sweepers to power through your team. These can all be played around, of course, as I doubt you have any replaceable member on the team.
At any rate, great job, and congrats on the peak!