I think the downside is that it might not have a lot of playability outside of Commander
7 Mirri, Weatherlight Duelist You Decide How Combat Is Going Mirri, Weatherlight Duelist makes it so that each opponent can only block with one creature when she attacks or only attack you with one creature when she's tapped, making it difficult for your opponent to prevent and deal damage
Some examples of this are cards like Alms of the Vein or Alchemist's Greeting, which arent really good cards for their original costs
Much of the detail is carried over to the card design, including its gold-coloured tsuba, or guard, and curving angle, which varies across depictions but is never entirely straight (as seen on the left)
I used to cheat death every day in practice
Storm is a bit of a tricky mechanic to work with, so make sure you practice plenty to make sure you get it right