Place eggs in a pot and cover with about 1 inch of cold water. Bring to a rolling boil over high heat, then immediately remove from heat, cover the pot, and let sit for 13 minutes. This gentle carryover cooking creates perfectly cooked yolks without that gray-green ring. Transfer eggs to an ice bath (bowl with ice and cold water) for at least 5 minutes to stop the cooking process and make peeling easier. Gently peel under cool running water, starting from the wider end where the air pocket is—this makes the process much smoother.
While eggs chill, drain the tuna thoroughly in a fine-mesh strainer, pressing gently with the back of a spoon to remove excess liquid and oil—this prevents a watery filling. In a mixing bowl, combine the mayonnaise, mustard, salt, pepper, Tabasco, minced capers, and onion powder. Stir well to create a cohesive base. I find that mixing these seasonings into the mayo first helps distribute flavors evenly rather than adding them to the yolks, which can create pockets of strong flavor.
Halve the chilled eggs lengthwise and carefully scoop the yolks into the bowl with your seasoned mayo mixture. Mash the yolks gently with a fork until no large lumps remain, then fold in the drained tuna until just combined—overmixing can make the filling dense and pasty. Transfer the mixture to a piping bag fitted with a small round or star tip (or simply use a small spoon) and pipe or spoon the filling generously into each egg white half. For easier piping, I like to cut a small corner off a simple plastic bag and use that instead of dirtying a pastry bag.
Arrange the filled eggs on a serving platter and dust generously with paprika for both color and a subtle smoky flavor. Serve immediately or cover loosely with plastic wrap and refrigerate until ready to serve—these taste best served chilled.