hi, whats better for jumps , a c-quad or a blade 3? I heard c-quads are a bit dangerous for jumping. Why?

Between the 2 you mentioned, I'd take the Blade. C-quads are not very stable and are likely to make unwanted maneuvers that could lead to injury.

Personally, I would suggest a stack of Flexifoil Super 8's for jumping (2-5 depending on the wind conditions). They are fast and controllable. Kite speed is what generates the type of lift favorable for kite jumping.

NOTE: kite jumping is the most dangerous form of kite traction and has caused more accidental injuries than all other kite sports. Do this on a soft surface (the beach) use pads and use your head. Seek advice from the pros first.

Doomwheels is spot on. The Blade is the better option. His warning is also spot on about jumping being a hazard.