To avoid this I suggest to fix it with an little modification. You should leave the system like it is with the RNG and weekly lockout but add one important thing. If a player cleared for example 5 or 10 times 1 turn (for example: T13) than he should get an item, let’s call it Token. With this item he can go to an NPC and trade the Token against the specific item which he wants (the NPC should all Loot of turns).

Player A cleared 8 times Final Coil of Bahamut Turn 13 he unfortunately had no luck that his weapon dropped. He is very frustrated and about to stop playing and find another game. But in 2 more kills of that Boss he know he will get the token and that token he can trade against the weapon he want. That way he stays motivated and keep playing.

I suggest making weapon token after 10 kills and other token, and for other turns after 5 kills. You can also combine the getting of this token with the archiving system.

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