Clearly the Snowman, half of the army has no rifles, the other half no bullets. twilight Sparkle vs. Hermoine Granger in a learning contest.
Twilight Sparkle. Hermione has only been properly exposed to magic since the age of eleven. Twilight, on the other hand, has spent the entirety of her life surrounded by and using magic. In other words, Hermione merely adopted the magic. Twily was born in it, molded by it. Lord Tirek (MLP:FiM) vs. Trypticon (G1 Transformers)
Trypicon, he's got no magic for Tirek to absorb, and the city bot's are know to take some tough hit and keep going so Tirek's got nothing to hit him with either. Voltron vs the original Megazord.
I like Voltron but, I think I remember he had a time limit of operation, so sadly the Megazord has clearly the upper hand. Sephiroth (FFVII) vs. Kefka (FFVI)
Hmmm... tough call, this one. While it's a very close match that could go either way, I'm going to go with Kenshiro simply because his attacks tend to make people explode in a shower of guts, gore and bone. Also, I forgot what Jotaro's Stand does to people. Mega Man vs. Megatron.
Without there armies? The Eggman. He's quite a bit bigger than Wily, with their armies. Wily he's smarter than Eggman. There is no bloody way Megaman would stand a change against Megatron. The Decepticon boss bot is a brilliant tactition and not only more heavily armed than Megaman, but more heavily armored. Willy Duwitt vs Zach (TMNT 1887)
Aquaman, they have essentially the same powers, but Aquaman can control fish. If they were on dry land then Namor hands down, but underwater Aquaman's one extra power give him the advantage. Mastadon Zord vs, Phil (from "Cro")