Here we go, into the mystical land of **Mathemagic**. Sorry if I goof up at all, let me know and I'll fix it ^.^

The Attack of a Lv 100 Mega Mewtwo X, with 31 IVs, 252 EVs, and an Adamant Nature is **526.**

Now, add the Huge Power boost.

**526 x 2 = 1052**

Next, multiply by 4 for the +6 boost.

**1052 x 4 = 4208**

Finally, add the Choice Band.

**4208 x 1.5 = 6312**

Therefore, a Mega Mewtwo X with the specified parameters would have a theoretical Attack stat of a whopping

#6312