Now here comes the fun speculation: what weapon or weapon combination does one use to hunt and kill Goto?

Guy already thinks he's invincible.
My proposal is a combination of sonic and radiation (microwaves) and ultra strong radar to discombobulate his senses and inflict deep discomfort while pelting him with long range armor piercing weaponry.

High velocity cannon fire would likely also help a lot

If that doesn't help, air strikes, missiles and napalm. Pic related would work best, except throw away any semblance of restraint and utterly cook him instead.