The thing about Diffusion Wave-Motion is that it's a situational card from my experience of usin it. Sure it's nice when you can get out that Dark Magician and then use Dark Magic Attack followed up by a Diffusion. But that's quite a few cards. Only really great for killing tokens and a lot of face-down monsters or monsters in general with.

Here, I'll just give you some suggestions of what to take out and what to add.

-DMG (blows, yes it blows...)
+DM (Hey, I've had good experience with three..)
-2 Apprentice Magician (You'll hardly get the counter, not worth replacing a weenie monster with a weenie monster...Just how I see it...)
+2 Toon Gemini Elf/Berserk Gorilla

You can squeeze Reflect Bounder or Exiled Force in there if you like. Wouldn't hurt at all.

-2 Diffusion Wave-Motion (Move one copy to side board...it's all you need anyway.)
-Smashing Ground (Horrible, just move to Side Board..)
+Enemy Controller

Don't ever use Reasoning or Monster Gate outside of OTK and FTK. You'll waste way too many cards. I've already tried it and it doesn't work.

I would add in Needle Ceiling and another copy of Sakuretsu Armor to your trap list. Just for extra removal purposes.

These are kind of strange suggestions, but they've worked from my experience. Try them, if they work then use them. =)

-1 Sage's Stone
-1 Controller
+2 Smashing Ground