Quote: "So for the end of my second level I have the power puzzle that after it's completed it opens a door by "If Used". But I would like to also have it turn off an animation from an entity (a power transformer)."
This should be in the script section...
The short answer is... yes it can be done. If the entity in question (power transformer) can turn on and off via a script, then you can create a script to not only open a door, but turn on/off the transformer. The key is to use the "settargetname=X" and "activatetarget=x" in the one script, and the transformer script would use a loop to check if the "activation" value was passed to it.
A remote door using "switch2.fpi" is a close example, except here you need to put the name of the door entity in the switch's "If Used" field for that switch to activate the door. But you can modify the switch to control a door and turn off an entity (if that entity supports a script to activate/deactivate animations)- all by using the above commands.
There's no problem that can't be solved without applying a little scripting.