Trinitrotoluene
young ☆nd foolish
I read a fan theory somewhere that proposed the idea that the Visionary is limited by its user's attention span, which basically means that Gremmy can only have so many things going on at once before older parts of the Visionary are cancelled out. Support for this theory is given when Yachiru's bones return to normal after Gremmy tries to seal and kill Kenpachi Zaraki in a crevass with water, all while imagining that massive slash Kenpachi dealt to him was healed. It forms an interesting limit IMO.