Introduction[]
In Xenoblade Chronicles X, there are these things called Ganglion Skells that have an insane speed feat. They are capable of crossing the Samaar Federation System within roughly 28 years (I'll explain this timeframe in the calculation itself). So, I'mma calc it.
Calculation[]
First, we need to figure out how big the Samaar Federation System is. Luckily, that's easy, as it is stated to span 6 million light years. So, that's our distance.
Distance = 6,000,000 light years = 5.6764383e+22 meters
As for the timeframe, I said it'd be 28 years. This is because I'll be assuming the Ganglion headed for Earth at the same time Elma arrived on it, which is a massive lowball given that the war was said to "eventually" reach Earth rather than Earth being an immediate target. How does this factor in? Well, in the ending, it's stated to have been 30 years since Elma landed on Earth. However, in the game itself, Earth is eventually destroyed, and there's a 2 year timeskip between Earth being destroyed and the game's ending, so that subtracts down to 28 years since the Ganglion were heading for Earth while it was still around.
Timeframe = 28 years = 8.83e+8 seconds
Speed = 5.6764383e+22 / 8.83e+8 = 6.42858245e+13 m/s
Final Result[]
Ganglion Skells Speed = 6.42858245e+13 m/s; 214434.43c (Massively FTL+)
XENOBLADE CHRONICLES X FOR THE WII U SWEEP!!!