Shadow Cloak
The shadows rise from Riku. The sun in his eyes as he finishes the seals with his right hand, his own shadow sliding up over his back, feeling cold. It slowly envelopes him, passing all over his skin...before he finally stands a creature of living shadow, only to step back into the shadow cast by the cliff, vanishing in it as he hides his physical form with his own shadow.
Rapid Decay
Riku walks alone into the desert, knowing that he is about to perform that which he is forbidden to use. He forms the seals with his right hand as he walks, practising, not yet ready to release the chakra. Alone now and standing before a boulder roughly the same size as him he begins to seal, pouring 'that' chakra into the Jutsu. As he completes it he feels the air change around him and slowly the boulder in front of him crumbles, falling down into sand as the field takes effect. Finally, standing before the pile of sand Riku nods to himself.
Shadow Constriction
Riku lets his nature chakra bleed out through his fingers as he forms seals with one hand before the coils of shadow leak up from beneath the tree lashing themselves to the branches and holding them in place against the blowing wind. Sand floats on the breeze and the tough desert tree ignores it as the shadows visibly wrap around it. Riku smiles to himself and releases the Jutsu. "This is how I will bind men."
Static Hands
Riku sits inside the Oasis, practising flashing through the seals. After he is comfortable with the one handed raiton sequence he forms it again, slowly the chakra flowing into his hands as the lightning begins to arc off his fingers until his hand crackles and sparks with the lightning contained, enhanced by his ability to deny the energy release. He looks up slowly then leaps at Katsuo who crosses his arms in front of his chest to take the blow before taking the sparking hand to the chest. Katsuo looks up from the sand and nods. It's ready.
Static Awakening
Riku smiles to himself. The Chuunin of Sunagakure watches as the lightning begins to arc off Riku's arms. He believes this is a Raiton Jutsu. Riku can see it in his eyes, he performs a few seals with his right hand for the Chuunin. Raiton seals. Fake. His left hand forming the true seals in his pocket. The denial of energy escape causes the overload, charging Riku with energy, his innate electrical abilities augmenting the raiton jutsu he is capable of. Finally the Chuunin nods his satisfaction and leaves. What a fool. He knows nothing.
Energy Redistribution
Riku stands with Rinako and Katsuo. He keeps them at a distance and forms the seals for his Arechi Release. Focusing on them both he creates vacuums within them that hold energy in as he forces the area around them to give up its energy. The result is energy rushing into the three of them as it drains from the area around them. The temperature drops but Rinako just smirks. Katsuo as stoic as ever nods his understanding. Two better teammates neither man nor god could have asked for.
Velocity Decay
Katsuo looks at Riku dubiously. He isn't sure of this but does as asked....and jumps off the cliff. Riku completes the sealing process and creates the field around Katsuo as he falls. Gravity tries to act on Katsuo, imparting directional velocity. But it's as subject to entropy as anything else and the energy dissipates almost as fast as it is imparted. Katsuos fall slows to the point where he lands in a small puff of sand. The risk proves its worth. Riku jumps.