I am pretty sure it is meant for the HK. Since they sell the metal case and the HK set together as one unit. I have no way to make sure since I only have the case 
Update: Just tried to put the FX Slayer set into the the metal case. It fits in but it doesn't look too good haha
Update: Ok eventhough their phone didn't work. Their email customer service works. They just sent me this email, so even if you ordered FX titles they will just send you the MI ones so don't bother (not that anyone would :p )
Seth Hiatt to me More options 3:34 pm (27 minutes ago)
We are out of the FX and can no longer get anymore as they have gone out of
business. The only one I have is the E-series. I can either send you that
one or refund your payment. What would you like to do?
At the end I am glad everything got settled. I took their offer, they are gonna send me the "E-series (MI)" Yuugi set which shouldn't be too bad . Lesson learned I am just gonna stick with CJV and Aniacs from now on ! 
Update: Just tried to put the FX Slayer set into the the metal case. It fits in but it doesn't look too good haha
Update: Ok eventhough their phone didn't work. Their email customer service works. They just sent me this email, so even if you ordered FX titles they will just send you the MI ones so don't bother (not that anyone would :p )
Seth Hiatt to me More options 3:34 pm (27 minutes ago)
We are out of the FX and can no longer get anymore as they have gone out of
business. The only one I have is the E-series. I can either send you that
one or refund your payment. What would you like to do?
At the end I am glad everything got settled. I took their offer, they are gonna send me the "E-series (MI)" Yuugi set which shouldn't be too bad
. Lesson learned I am just gonna stick with CJV and Aniacs from now on !