Just an additional tip, you can also get Giga Drain on Ludicolo without using up a TM by breeding with Shroomish or Sunkern. Some other pokémon also learn it naturally, like Treecko, Paras, and Roselia, but they're not available in Emerald if you choose Torchick. Shroomish also gets Leech Seed naturally, so you can get both moves from the same breeding chain.
Master balls are the cheapest thing ever invented. It's more fun catching everything with balls that can fail. 'caught Latios in the wild without master ball ftw'