I used the Charmander one recently. It took me for a while to actually use one because the packaging is so cute! The sheet mask itself unfortunately does not actually have a Charmander head (that would be funny though).
It had the pleasant citrus smell of grapefruit and did noticeably brighten up my skin right after. I haven’t tried the rest, but I’m looking forward to it as I follow this year’s resolution of using things up!