Hi @Symnoian, I had a similar requirement. and it is fairly simple to implement.
Step 1: I performed a Get Row by ID action on the email templates entity. and I used it in the Instantiate Template Action. I am also passing the Entity (Case) for which I am running the email template. I have also defined an Object type of variable to hold the body of the unbound action.

Step 2: now I got the object shown in the below image as the output from the unbound action, I used this object to create a Schema in the parse Json action.

I parsed the object from the unbound action with the provided Schema. and I get the Subject and Description that has been create by the email template.

then I am just creating an email message using and using the add a row action and adding the Subject and Description in that email message. this will just create an email message if you want to send that email there is another bound action to do that.

Hope this solves your issue