Name: Unknown
Kido Number: Forbiddan (As in Event Only)
Incantation: Something really long...if I can think of one that is really long, I'll fill it in...
Effect: Two yellow seals show up, one above and one below. fifty rods of light comes from each seal, 25 on the inside, 25 out, and start spinning in opposite directions. The victim is in the middle. After 2 posts? (if I can get away with it being shorter, I'll take it), the seals and rods constrain the target and goes into a completely different dimension, leaving no trace behind. It then sucks the victim's energy to continue powering the spell at a neutral rate (they recover just as much as they lost), keeping them there indefinitely with no way out.
Unfortunately, it's not without its downsides. Riku faints and his pendent gets a huge gash in the middle, destroying any effects it had. Riku also loses all of his memories and takes a huge power decrease for a while, where he is only 3-1 or 2-5, and no shikai/bankai/toukai to start with (and will regain those faster than his original tier). He wouldn't even know his own name.
When he faints, the pendent will leak energy. Miyuki, Riku's mother, will appear and explain what happened, reveal that she succeeded Tessai before disappearing to be with her hubby, how she created the spell to some extent, why she created it, and imporing them to take care and have patience with her son due to the side effects. She would then disappear.
Who can use it: Riku and Riku alone. After this is used, he DOES NOT have his pendent's effect of lowering his kido cooldowns by 1 anymore.