This is a great story. Props for killing Blaziken with Mienshao. Haxorus, as expected, is a BAMF, though admittedly I prefer to use LO + SD + Mold Breaker instead of CB + Rivalry. Then again, CB is more effective against Quag. Loved the lol pictures, too. All in all this gets a 9 from me.
Yeah... Timid Specs Latios can't even 2HKO a healthy Careful Tar (I presume that's what your opponent was using, that's what it looks like to me) with Surf, and Modest LO fares even worse (1.1 x 1.3 = 1.43 < 1.5).