It is normal to see other characters from other games appear in the Super Smash Bros. game but the latest one was a little unexpected.
It was announced that Lotus, the character from the FTP shooter game Warframe will be added to the game as a Spirit. The new spirit was announced on their Twitter account. Lotus will be appearing from the 23rd of February until the 3rd of March.
The Spirit Board event is called Strength not Dyed! Black Spirits and will feature some other characters including Pokemon, Bullet Bill, and Game and Watch characters. Lotus will able to supercharge at level 99 but to claim her, you will need to fight Bayonetta as part of the event.
This could also mean that Lotus will be one of the six DLC characters coming with the Fighter Pass Volume 2.