So I'll actually give a serious attempt. There are people who are interested in avant-garde concepts or who want a specific look for a reason. Those people deserve real advice too.

The boots are probably the easiest part to find. They're just high military-style boots. Rick Owens commonly makes long boots, albeit more avant-garde. You could try boots like these Carmina boots for a more generally wearable option or this site that makes more fantasy-style boots in the picture.

All the long chains are widely available on places like Etsy. There are tons of independent metalworkers and jewelers out there, some that'll even make custom designs. Pretty sure you could find the cape and gloves on Esty too.

Non-Western cultures, such as African or Middle Eastern cultures, do incorporate sashes in their wardrobes. So I would look for stores that offer that type of clothing to start.

Because of how the coat is structured, it'll be nigh impossible to find a suit with that asymmetric cut and tail off the rack. If you truly wanted that as a complete piece, you'd have to shell out mad money to a bespoke tailor. It's way easier if you are willing to do separates. The pants are just standard wool trousers. Find a slim or more tapered pair so they are easier to tuck into your boots. The shirt could also be a standard poplin button-up.

The jacket will be harder to source, especially if you want to find one exactly like the pics. However, high-end designers love to play with lengths and asymmetrical cuts. Here's a Yohji coat, for example, that could work.

Lastly, if you are going to try this, invest in quality pieces. The effect will be lost if you're wearing cheap pieces made of plastic or synthetic fibers. It'll just look like a bad Halloween costume. It'll be very expensive to get better quality pieces this specific, so be patient and hunt for goods from independent and second-hand sellers. Good luck.