Before you can even attempt to snag this trophy, you need to purchase the Tanegashima from Drebin. That means you will need 1 mil Drebin Points OR 800K on Sundays and Wednesdays OR you can wait until Act 5 when it is even cheaper.
If you want to farm Drebin Points, I highly suggest the first indoor area on Act 4 (Shadow Moses). Here you have a bunch of the three armed little robots (forget what they are called
) that all have GSR's, except for two that have shotguns. Best thing about these little guys is, they never reload their guns: instead they toss them aside and magically get a new one. So all you have to do is get their attention, roll around a lot, and pick up the guns they toss to the side. You can get 800K, or even 1 mil, easily. Just make certain you do this on Liquid Easy on your Chicken emblem run
.
Anyway, once you have the gun, you need to get to a place outside, open and windy. I highly suggest waiting until a New Game+ for this one, simple because Act 1 and Act 2 have the best areas to cause a "Divine Wind".
Equip your Tanegashima, aim for an enemy combatants head, and hope for the best. A Divine Wind, under the conditions above, has about a 1 in 4 chance of activating. You will know it has occurred because a tornado will appear sucking up all the enemies around the guy you just popped in the dome.
Questions, corrections and neg vote justifications below.