In KOF 2000 (if I'm not mistaken) during the NESTS's Saga period, as Kyo became the striker for his team(?) (Daimon, Benimaru, Shingo and Kyo) he just wiped both Mary and Terry out of the stage at the same time, and Terry was thrown to the audience's seating walls with just one attack when Kyo rushed to aid Benimaru. That time, Rock was still a kiddo. And that's Kyo when he's raged.
At the same saga, after being thrown out of the ring by K9999, Iori (Iori, Vanessa, Seth, Ramon) returns and beats Ralf in just a fraction of seconds after appeared in just in the blink of an eye, pushed Leona off the stage with his eerie aura which left her in fear, and defeated Heidern without even touching him, just using the illusions.
After Iori regained his power back, he killed his teammates, the last time I heard.
Seriously, Iori shouldn't be underestimated. In game or storyline, he's on his own league. And he didn't hesitate to kill anyone that stands in his path.