Power Toggles supports creating custom toggles using tasker. These toggles can show on/off state, counters or even multiple states with different icons for each state.
Check out this fan made video tutorial for creating tasker toggles
Note that in PowerToggles there would be two options for Tasker.
Following pictures describe a sample toggle which shows a notification when activated and removes it when deactivated.
Create a new tasker task and add an action Alert > Notify.
Make sure to set the if condition to %state is set
Add another action Alert > Notify Cancel
Make sure to set the if condition to %state is not set
Add the PowerToggle Plugin action from Plugin > Modify PowerToggle state
Configure the plugin to set the current state of the toggle to new state. The current toggle is automatically taken based on the running task. The new state is automatically set to the desired state. You can also set the state to a more specific on/off state (like if you are using the if condition)
Your final task should look like the image above
Now in PowerToggles widget config screen
select 'Add Toggle' and select 'Tasker Toggle'