A Ninja Shitblast is a combination of a Ninja Blast and a Shitblast, A
Ninja Blast is when you eat a any combination of eggs, bread, prunes, prune juice, mexican food, or indian food, and then eat a bunch of laxitives.
When you need to take a shit real bad after than, you then proceed to go to an enemy's house (preferably sneak in, hence the "Ninja" aspect and shit not IN thier toilet, but SHIT BLAST all inside the resivoir - you know, the top where all the workings and floater and stuff are.
After doing that you then take a HUGE MEGASHIT in the actual toilet itself and stuff it full of toilet paper to plug it up. Then you flush it and it will overflow with shit and the owner of the toilet will NEVER be able to clean it and it'll smell like shit forever until they replace the toilet.