Switchable death blocks
See this pack. In particular, the switch_kill.asm file is what you want. You'll then want to open up the ASM file and change these settings at the top:
Code
!switch = $14AD ; $14AD = Blue P-Switch, $14AE = Silver P-Switch ; $14AF = ON/OFF Switch, $1F27 = Green Switch ; $1F28 = Yellow Switch, $1F29 = Blue Switch ; $1F2A = Red Switch !reversed = 0 ; Reversed conditions? 0 = false, 1 = true.
These will control what "switch" toggles the block's interaction.
Note that this only handles the interaction and not the graphics, though. For the graphics, you'll need to use ExAnimation.
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