Are you going to be speaking the word, or only writing it?
Many Japanese words are difficult for foreigners to pronounce correctly. In the case of "superior", there are a couple of Japanese words with this meaning that are easy to pronounce and also happen to sound cool to a western ear:
tobikiri (toe-bee-kee-ree), and
hitokado (hee-toe-kah-doh). I would recommend one of those two if you will be speaking the name.
In the Japanese writing system (kanji plus other characters)
there are several ways to write each of these. One example for each:
tobikiri: 飛び切り
hitokado: 一廉
Although it is non-standard, you could also write the first one more simply as 飛切. If you are doing this more for decoration than for communication, this short version is fine.
If you are only going to be writing the word, and you don't care at all how it sounds when spoken, there are more options available.
