After beating your Latias, look for the following CP values. These values are those of a Latias with perfect IV's.
Latias has 228 attack, 268 defense, 160 stamina. As a Raid Boss, it has a CP of 45704.
Latias is a Dragon-type and a Psychic-type. It has access to the following moves:
Other viable counters
Heracross and Pinsir are good Bug-type alternatives to Scizor. A Sceptile with Fury Cutter can also be used.
Banette and Gengar are the best Ghost-type counters to Latias. As for Fairy-types, Ursaring and Clefable are usable.
Walrein and Lapras are goof Ice-type alternatives. Feraligatr and Miltoic can also be used.
Dragonite and Salamence are great Dragon-type options. Altaria and Flygon can also be useful.
Absol, Gyarados, Umbreon, Sharpedo, and Houndoom are the best Dark-type counters.
IMAGE CREDIT: The Pokémon Company