The Tai Chi sword, known as the Jian is more complex than most forms of swordsmanship. For the Tai Chi practitioner it is about projecting your energy down the sword itself.
I’m sure that some will argue about it’s practicality. I don’t know enough about it to really comment on that aspect, though I do believe it would be lethal in the hands of a real expert. Here it is demonstrated by Damo Mitchell, author and founder of the Lotus Nei Gong Association.
Despite the huge popularity of martial arts today, it is still quite rare to find somebody who can handle the Jian with expertise.