12th game Unforgiving Trials: The Darkest Crusade - 2 keys
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13 -mix horror hospital janitor wyatt derp 2 arcane war -5 keys
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14 -mix2 zombie boom blockstorm unforgiving trials the space crusade yellow artifact - 5 keys
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And finally the last and biggest one!

15 -MIX3 The Descendant > Lost moon Sleengster dead ivan tap heroes alter world spheroid freebie -9 keys
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Thanks a lot! Took the first Key of "Unforgiving Trials".

Please let me know if all keys gone

thanks! I took 15 -MIX3 8th key "freebie"; 3, 4, 6, 7, 9, have been taken.

One more bumb just in case
because i do not know exactly is here any key left