When a system adds kata from other styles of training, IMO it would be best if they document the source for students. BTW there are often various ways to spell the same kata.
I recognize the name Yansu from Kyokushin Karate (the only system that uses it as far as I know). And as Kyokushin also teaches Saifa, perhaps they have the same source.
But Saifa was originally a Goju Kata (then imported into Shito-Ryu and finally Kyokushin)
Wansu is likewise used by multiple systems, with different shapes to the form.
I've pulled some various sources for you to consider if they are similar to yours.
Yansu Kata – Kyokushin Karate of Mas Oyamahttp://www.uskyokushin.com/kata.htm
Yansu is derived from the characters Yan, meaning safe, and Su, meaning three. The name is attributed to that of a Chinese military attaché to Okinawa in the 19th Century. The word yansu also means to keep pure, striving to maintain the purity of principles and ideals rather than compromising for expediency.
Yantsu Kyokushinkai katahttp://www.youtube.com/watch?v=TYFP3vZK_jchttp://www.youtube.com/watch?v=MWquXWzZJxg
Saiha means extreme destruction, smashing or tearing. The word Saiha can also mean great wave, the source of the IFK logo. No matter how large a problem is encountered, with patience, determination and perseverance (Osu) one can rise above and overcome it, or smash through and get beyond it.
Saifa Kyokushinkai katahttp://www.youtube.com/watch?v=jBSOGmIRoBs
Karate Goju Ryu – Saifahttp://www.youtube.com/watch?v=l-guWxDMC94&feature=related
Saifa Shito Ryuhttp://www.youtube.com/watch?v=hh94MDo4mKQ&feature=related
Wansu (Wanshu) is one of the most popular forms among Okinawan systems and has been used for many years, undergoing many modifications. Even today, there are several variations of this traditional form. Wansu, is said to have been named after a Chinese envoy to Okinawa who happened to be a martial artist. It is believed that Wansu originated in China around 1690, making it one of the oldest Okinawan forms. Wansu was primarily used around the village of Tomari and therefore part of the Tomari-Te system. There is also a Chinese name that the form is translated to mean Flying Swallow.
The kata includes a distinctive upper level attack followed by the defender grasping the opponent and drawing him inward, simultaneously jumping in and attacking again. This movement resembles the up and down and flipping away flight of a swallow. http://www.hathagojuryukaratedo.freeservers.com/photo3.html
Wansu – Isshinryuhttp://www.youtube.com/watch?v=zyJBYI4CM2w
Wado Ryu Wansuhttp://www.youtube.com/watch?v=ZmKYDG_TkUM
Seibukan Wanshu Katahttp://www.youtube.com/watch?v=3zo1emnRwN0
Wansu Okinawan Kempo http://www.youtube.com/watch?v=PEgi3wfJHeU