When I'm really lost on what to do with a design, I scribble something with a ballpoint pen on notebook paper. Not having the pressure of making a finished piece frees my mind to create without freaking out.
In these sketches for the Tower of Power, the main "hero playset" of the line, you can see some obvious influence from the Grandmaster Tower seen in Thor Ragnarok as well as the monumental architecture Jack Kirby imagined for the Lord of Light movie sets/theme park project. There's also some initial sketching of their main vehicle, tentatively called the Thunder Chariot like in Lord of Light.