Xen
Wi-Fi Leader
Maybe more suited for the Unpopular Opinions thread, but Truant is fine for Slaking imo. It still dominates in-game as long as you know how to play around the ability (or if you play with the Shift option on, it's flat-out trivial). The ability presents more of an issue for battle facilities and link battles, but it can still be usable as a Choice user at least. Or better yet, take it to the Battle Hall in Gen IV where it's right at home.
Really, the most annoying thing about Truant is the fact that Slakoth has it. Unlike Slaking, there's no real reason for Slakoth to have it, and it makes leveling it up early-game a huge hassle for a Pokemon that supposedly can fight on its own (unlike Magikarp). It makes the payout seem less worth it when you can just train a Magikarp and evolve it into a powerhouse that doesn't carry any handicaps.
Really, the most annoying thing about Truant is the fact that Slakoth has it. Unlike Slaking, there's no real reason for Slakoth to have it, and it makes leveling it up early-game a huge hassle for a Pokemon that supposedly can fight on its own (unlike Magikarp). It makes the payout seem less worth it when you can just train a Magikarp and evolve it into a powerhouse that doesn't carry any handicaps.