If you fancy strapping some big iron balls to your fists so you can throw a more effective punch, you might be looking for the Iron Ball Fist Weapon. This is one of the few fist weapons found in The Lands Between, and they can be a powerful tool if used properly. This is where you get the Iron Ball in Elden Ring.
To get this fist gun you need to kill the NPC called Blackguard Big Boggart. He lives in the Boilprawn Shack in Liurnia. To get there you must either complete Stormveil Castle or bypass it and go down into the Liurnia lake area.
Killing Blackguard Big Boggart brings some rewards. You will get the Iron Ball, the Iron Mask, the Black Guard Bell Camp, and 1,000 Runes. Defeating Blackguard is not difficult. He is easily stunned and his attacks are easy to avoid. You can also kill him as part of Rya’s quest line to get Rya’s necklace. This will give you an invite to Volcano Manor at the end.
https://www.gamepur.com/guides/how-to-get-the-iron-ball-fist-weapon-in-elden-ring How to get the Iron Ball handgun in Elden Ring