What is a power complex? Yes, it’s something I made up. But it can be applied in Pokemon almost all the time. Defining a power complex is simple: it is a desire for power; much like a God complex is a desire to become God. We know about this because of how many want legendary Pokemon either in the game or in their teams, and do not pay any attention to certain kinds of moves in battles, relying on the strongest ones (like Hyper Beam or Giga Impact).
Of course, a solid set of stats are good, but having the right moves are even better. Even I went through this once, voluntarily removing all the status and stat-changing moves, thinking they would do no good. However, once I got the chance to learn more about the various kinds of status conditions, I learned that incorporating status moves into a moveset will be very beneficial.
If you’ve been to the Battle Subway, Tower, etc., you will see that the farther in you progress, the more strategic your opponents will become. This is because brute force will simply not be enough to win a battle. One must use strategy, which is why status moves were created. A classic example is using Toxic, and immediately using Protect the next turn, thus slowly defeating one’s opponent.
In the Towers/Subways, your opponents tend to use Pokemon that support each other, or that do not interfere when certain moves are used. For example, using Bulldoze with a Flying-type partner helps since Ground-type moves will not affect Flying-types. An experimental strategy I used in the Battle Subway was to have Lanturn out with Zebstrika. Since Lanturn is naturally slower, it would be hit before it could use its move, that’s why I had Zebstrika use an Electric-type move on it. Lanturn’s Volt Absorb ability would then convert the damage into HP. But seeing as I had only Surf that would be effective against Ground-types, I decided not to risk using this strategy.
Today, while fighting the Multi Train opponents, I came across a stubborn Cradily that kept using Stockpile, which would raise Defense and Special Defense, making it even harder to knock out. After three turns, it would use Swallow to recover all of its HP. Another example would be to use Ingrain, Leech Seed, and then repeating Giga Drain. Although this would take three turns to implement, the results would turn the tides of battle, especially if your opponent has more Pokemon weak to Grass-type moves. (Remember, Leech Seed does not affect Grass- or Bug-type Pokemon.)
After all this, it may be too much to immediately change your path. If you’ve been finding it difficult to defeat others, then (slowly) try to experiment with TMs or HMs. You would never find anyone at the Pokemon World Championships using only physical or special moves; they have their own strategies. Although most of those battle plans have been leaked out to other competitive battlers, there are numerous combinations of ways to keep your opponent on edge, so don’t be afraid to try and experiment with them.