The first idea that popped out was to engineer an anti-missile device, and he just so happened to know a basic blueprint for a pure defensive device, which was called expandable light fortress. It could suddenly form a golden shield that protected the target and blocked the explosion and shockwave.
There were a variety of blueprints for defensive machinery, and the most common one was the energy shield. However, knowledge on those shields required class advancement in energy studies, and this type of light fortress did not require a high level of skill. One only need the blueprint and some basic understanding to create the design in the blueprint, and the defensive durability would be dependent on the materials used.