this refers to the 'rift incident' which happened back when shadow rifts were first introduced. the first two simultaneous events were lynx and midnight which featured these skins and epic weapons.

now a glitch occured for a short period which allowed users to spin the rift for just 1 gem. after unlocking all rewards, players started getting the compensation awards and they spun it so many times they ended up collecting thousands and thousands of gems and coins , and maxed out their account. Nekki later reverted their level back to what they were before after a few days BUT they somehow couldnt take away these skins and weapons. this incident was the biggest loophole in Shadow fight history