I'm sorry, I doubt your loan will be returned. It appears that he had many accounts which he mostly used to gamble and collect from giveaways.
Here are some of shark313's alt accounts:
Alicia90
RyanBraun
spurs32
ropegut
Breakstuff
Coldcase

Shark313 has posted the address 156ifGhzVgHWzKSXxQSf96cbcnPtmptFF4 on bitcointalk and the address 1Fw5U7p1tvD7gvS3kgQJ2xu26BhdU3GJ2X on this site (https://bitcointa.lk/threads/offering-free-bitcoin-mining-1-btm-each-post-your-address-to-receive-merged.150270/page-6). RyanBraun also posted the address 156ifGhzVgHWzKSXxQSf96cbcnPtmptFF4 on that page. Alicia90 has posted the address 1Fw5U7p1tvD7gvS3kgQJ2xu26BhdU3GJ2X in this thread (https://bitcointalk.org/index.php?topic=260593.msg2780551#msg2780551). Spurs32 has also posted the same address here (https://bitcointalk.org/index.php?topic=217216.msg2590008#msg2590008). Alicia90 also posted the address 19KRH4ZMQFU59YaquD7Y1qYRD62yMAa2cZ in this thread (https://bitcointalk.org/index.php?topic=224482.msg2614043#msg2614043). That address was also posted by ropegut in this thread (https://bitcointalk.org/index.php?topic=255435.msg2787129#msg2787129) and by Breakstuff in this one (https://bitcointalk.org/index.php?topic=259765.msg2812655#msg2812655). Ropegut posted the address 1NgjehCkTKZzajpKgP4Kcaz9pRUJTWeNki here (https://bitcointalk.org/index.php?topic=259765.msg2782755#msg2782755) which was also posted by Coldcase (https://bitcointalk.org/index.php?topic=224482.msg2614034#msg2614034).

Sorry for the cluttered paragraph of links and addresses.