To clarify, here is the summary of the Katana series, which explains the antagonists
"The spirit of Katana lies in the true Samurai of long ago; both those trained to protect nobility and the clans that rose in the countryside to protect villages. They were ruled by codes of honor, bravery and selflessness, but over the years many devolved into assassins for hire. Katana will encounter and battle modern day versions of ancient clans, the Sword Clan and Dagger Clan, and her antagonists will include SICKLE, COIL and SHACKLE, men who have mastered their preferred weapons."
That sounds pretty fine to me. Here is the Vibe one too:
"When we meet him, he has no plans to be a superhero. But when his powers become known to A.R.G.U.S. and Amanda Waller, Cisco is recruited by AGENT DALE GUNN. Detroit is an inter-dimensional hot zone. Any number of beings and creatures are able to enter our dimension through the motor city. Cisco is the only one who can sense these incursions... and fight them. And so, to save our dimension from dark forces from beyond our Universe, Cisco becomes the super hero known as Vibe."
That one sounds really interesting.