Ryuuga

Ryuuga is a staple move across all Kyokugenryu Karate practitioners, being introduced in the original Art of Fighting and being a core component of Robert Garcia's moveset.

Description
The user does a jumping uppercut with their rear fist. The animation and level of technique varies from user to user, but functions the same across all characters that use it.

Strategy
A very strong and effective anti-air, this is your strongest option against an overly aggressive opponent that is recklessly trying to jump in on you. More often than not, it's also a very reliable and damaging combo ender.

Surprisingly enough, the move is actually not too difficult to cancel into Haoh Shoukou Ken or the Ryuuko Ranbu. For the former, after the initial DP input, you can do a input immediately after, since you already performed the first part of the motion. For the latter, it's as simple as doing the move as +  then immediately doing  +. Make sure the opponent is in a range where the move will connect, though; in some cases it's liable to whiff.

Trivia

 * If the Ryuu-Geki Ken is the Kyokugenryu equivalent of Street Fighter's Hadouken, then this is the equivalent of the Shoryuken, serving the same purpose and more or less functioning the same across all its users.