Fighting kites do not have blades. In the "old country" (especially India), they do use cutting string called Manja, which has ground glass and paste applied to cotton or linen line, and they slice each other's lines in a huge free-for-all from multiple rooftops. The kites are typically flown so high that they're almost out of sight. Some immigrant groups carry on this activity in North America, but most of the fighter kite "fighting" is what's called "line touch", usually on relatively short lines. Basically, two fliers stand side-by-side and take turns choosing, and yelling, "over" or "under". If it's "over", the first one to touch the top of his/her opponent's kite string with his/her own kite string wins; . . . "under", . . . bottom. . .
There's also some figure competition in fighter kites -- like the "precision" figures for stunt kites and quads -- though I've never seen it or read much about it. Go to the left edge, spin 5 times, go straight to the top centre, spin twice clockwise and twice counter-clockwise, go straight to the right edge and spin 5 times. . . one point deducted each time you have to repeat an attempt to get it right -- that type thing, I think.
The most "with it" fighter kites seem to be (IMHO) Indian, Indonesian, modern designs based on those two, and a (Japanese?) horizontal rectangular design called the Buka. There's a ton of information on fighters on-line, partly because it's been tough to buy a good fighter kite in the US or Canada, so most fliers have been making their own and sharing info. The Northwest Fighter Kite Association (NFKA) has an e-mail list-serv that anybody can subscribe to, with maybe 5 or more messages a day, on events, materials, designs, and techniques.
Here in Toronto, there are a number of excellent fighter kite fliers, and they can practically write their names in the sky with their kites. There are also a number of people flying fighter kites indoors, though I haven't witnessed this yet. Jeff Howard of PKC, the maker of the Indoor Wren and the Pro Wren SUL stunt kites, also makes some excellent fighter kites in the $40-$80 range, including an indoor fighter near the bottom of that price range. Into the Wind and Gone With The Wind now carry good fighters, so it's not impossible to find them in North America. At the year-end get-together of the Toronto Kite Fliers, I just bought some excellent bamboo-and-paper India Fighter Kites, from India, for one Canadian dollar each! (That's about 63 cents US these days!)
Many of the local hotshots tend to fly dual or quad kites when the wind is strong and/or steady, and fly fighters when the wind is light and variable or dirty. Fighters can be designed for remarkably strong winds, too, and some folks fly fighters in almost any conditions.
Early in 2002 he NFKA decided to adopt a single kite shape as a "one-design" for a second, parallel track in competitions. This is in addition to the "open" competition in which each flier flies any kite(s) (s)he chooses, commercial or home-made. The idea is (1) to have the contests a purer test of flying skill rather than design and building skill, and (2) to facilitate information sharing, since a bunch of us will be trying to maximize performance with virtually identical kites. I argued for a commercially available kite, but they opted this year for a design, to be home-made. The design is on the NFKA web-site, and it's the design that Bruce Lambert used to win this past year's "World Cup". It can be made in various materials and stiffness, to accommodate any winds. Bruce says a light-bowed version he made even flies well indoors!
The best sites for fighter kite info are the NFKA's at:
http://www.fighterkites.org
and one called Cyberfighter Website, at
http://www.csun.edu/~hfoao033/fighters.html
Jeff Howard's commercial fighters, the Aerostar Stryke, is getting very good reviews from reliable sources, and prices start at US$38
http://www.aerostarsportkites.com