If I get it correctly: you may use around 200 BTC or 5m USDT as a collateral with this "Ledn" guys and they will transfer 2.5 mil to a property agency to buy you a house (no idea about their fees and the quality of the property deal itself). Then you can start the paperwork to get your residency (no idea on price/time here). And you only pay 12.9% annually to maintain your loan or your collateral will be liquidated (some losses here for sure).
So the only "good" thing is that you don't need an actual bank to pay for the purchase itself. All for just 12.9% per year.