Bloodnium is considered to be an endgame currency. It can be found reliably on the endless floors of TENGOKU. Alternatively, one can find varying amounts of Bloodnium through consuming Splattershrooms found anywhere in the Tower of Barbs.
Splattershroom variants
Splattershroom
The smallest Splattershroom variant. Gives 10 Bloodnium to the player upon consumption. May be found lying around in the Tower of Barbs.
Big Splattershroom
The mid-tier variant of the Splattershroom. Gives 100 Bloodnium upon consumption. Once the 50th floor is unlocked, a weekly quest will be unlocked which rewards the player with 3 Big Splattershrooms for reaching the 60th floor. Additionally, Big Splattershrooms may be found anywhere on the Tower of Barbs.
Mega Splattershroom
The largest possible variant of the Splattershroom. Gives 1000 Bloodnium upon consumption. A weekly quest may be unlocked which gives the player 1 Mega Splattershroom for climbing to the 80th floor of the Tower of Barbs. This quest may be unlocked by finishing the "Climb to the 60th floor" quest. No proof has been found that this type of Splattershroom may be found within the Tower of Barbs.