you don't have to load the value if it's an nop just use the zero register. Also, you don't have to load the first half of the value if it's an nop too just load the 2nd half of it.

lui t0, $[controller address] //loads the first half of controller address in t0
lui t1, $08d0 //loads first half of knife code to t1
lw t0, $[controller address] (t0) //loads the value of controller address into t0
ori t2, t2 $0100 //loads the off value of knife code into t2
sw t2, $44d8(t1) //saves the off value to knife code
ori t3, t3 $[Button value] //loads button values
bne t0, t3 $[to jr ra] //branches to jr ra if button's are not pressed if they are it processes the commands under it
nop //no operation
sw zero, $44d8(t1) //saves the on value to knife code
jr ra //ends command

anyways hope this helps you learn more about commands. also,good job with this.