Heat oil in a large nonstick skillet over medium-high heat. Add onion and garlic powder, and sauté 3 minutes or until onion is tender. Add veggie crumbles, salt, cumin, chili powder, and green chiles, and cook 5 minutes.
Prepare egg rolls:
In a small bowl, whisk together the egg, water, and cornstarch.
Working with one egg roll wrapper at a time, place about 2 tablespoons shredded pepperjack cheese and about ¼ cup filling on each egg roll wrapper. Brush some of the egg mixture on the edges of the egg roll wrapper. Roll up the egg roll, folding in the sides so that the filling is contained. Brush the egg mixture on the outside of each egg roll.
Repeat procedure with remaining egg roll wrappers, filling, and cheese.
Preheat air fryer to 400° F.
Place the egg rolls in the air fryer basket in a single layer. Air fry at 400° F for 8-10 minutes, flipping halfway through, or until brown and crispy. Serve warm with guacamole or queso if desired.