I personally am loving Tyrantrum in the main game, and, in my opinion, as a part of a Sandstorm team it may be able to function as a bulky sweeper due to the 50% Special Defense Increase, helping cover it's weaker of the two defense stats it has. In fact I've had an even easier time by also using an Assault Vest held item, it's great for making a bulky sweeper even bulkier if it's lacking in Special Defense, the downside of course being that it will be unable to use any pure buff or support moves.
And I can personally say that, with a Female Tyrunt/Tyrantrum and a male Tyranitar/Ekans/Arbok with the proper moves, Tyrunt CAN get Fire, Ice, and Thunder Fang all at once through breeding (Heck, while breeding for one with a decent Nature I got about a dozen of the suckers, I then proceeded to fill the Wonder Trades with them, and even then my best hatch so far has been a neutral nature with above-average IV's, still no complaints), and assuming Poison Fang too if you give up one of those slots, and obviously by extension Tyrantrum. I'm none too good with the in-depth calculations though, I'll leave the super technical stuff to others.
To be honest, my only regret for Tyrantrum is that they never introduced any STAB-based bite moves for Gen 6 to compliment it's Ability even further, or a steel type bite based move to let it tear through fairies with ease, as steel is, even with poison's new power against fairies, a better offensive coverage type, having 3 Super Effective coverages instead of poison's 2 (and grass is, half the time, covered by a secondary poison type or something similar, plus the fact that a few new fairy types are also covered by the steel type as well, making poison get barely any buff if you ask me)
And I can personally say that, with a Female Tyrunt/Tyrantrum and a male Tyranitar/Ekans/Arbok with the proper moves, Tyrunt CAN get Fire, Ice, and Thunder Fang all at once through breeding (Heck, while breeding for one with a decent Nature I got about a dozen of the suckers, I then proceeded to fill the Wonder Trades with them, and even then my best hatch so far has been a neutral nature with above-average IV's, still no complaints), and assuming Poison Fang too if you give up one of those slots, and obviously by extension Tyrantrum. I'm none too good with the in-depth calculations though, I'll leave the super technical stuff to others.
To be honest, my only regret for Tyrantrum is that they never introduced any STAB-based bite moves for Gen 6 to compliment it's Ability even further, or a steel type bite based move to let it tear through fairies with ease, as steel is, even with poison's new power against fairies, a better offensive coverage type, having 3 Super Effective coverages instead of poison's 2 (and grass is, half the time, covered by a secondary poison type or something similar, plus the fact that a few new fairy types are also covered by the steel type as well, making poison get barely any buff if you ask me)