Hi there Xelested, welcome to Smogon. There are four things that competitive battlers will look for that people just playing in-game usually won't care about.
1. Nature - there is an optimal nature for each Pokémon set. For virtually all competitive Latios, that is Timid, so you generally wouldn't train a Latios for battling purposes unless it was that nature.
2. IVs - Obviously, it is near impossible to get perfect IVs on your Pokémon like you can with Shoddy Battle. However, 28 or better in the most important stats (for Latios these would be Special Attack and Speed) and 20 or better in HP and the defenses (since Latios should be running only offensive sets) are what a competitive battler would look for. (I don't play Wi-Fi, so those numbers may be slightly off!)
3. EVs - Once you have the nature and IVs you want, you have to EV train your Pokémon. For Latios, a simple 252 SpAtk/252 Spe/6 HP approach is usually the best, although it obviously depends on what set you want to run. It doesn't require any luck to get optimal EVs, just time and making sure you battle the right wild Pokémon!
4. Moves - In-game, you probably use Dragon Pulse and three other coverage attacking moves on Latios, or you may use it as an HM slave, or a combination of the two. Competitively, you would want different moves (again depending on the set you want to run), although some (like Dragon Pulse and Surf) are still great.
Essentially, your Latios differs from one that would be used by a Wi-Fi battler in that it hasn't been meticulously picked out through SRing (for nature and IVs) and trained (for EVs and moves). Here's the link to Smogon's Latios analysis:
http://www.smogon.com/dp/pokemon/latios As you can see, there is a specific combination of nature, IVs, EVs, and moves that is the "best" for each competitive Latios set (although there is always room for personal variation!). These combinations are what Wi-Fi battlers will train for that in-game battlers like yourself won't.
I hope that answers your question. If you have any follow-up questions, feel free to ask!