For more information, please check the forum thread here.

7th Anniversary Event 2022 Milestone Rewards
 Total amount of enemies vanquished: 2,187,310
 +5% Drop Anything Rate  250,000 kills needed!
 +10% Rare Enemy Rate  500,000 kills needed!
 +5% Rare Drop Rate  750,000 kills needed!
 +10% Experience Rate  1,000,000 kills needed!
 +10% Rare Enemy Rate  1,500,000 kills needed!
 +5% Drop Anything Rate  2,000,000 kills needed!
 ? ? ?  2,500,000 kills needed!
 ? ? ?  3,000,000 kills needed!
 ? ? ?  3,500,000 kills needed!
 ? ? ?  4,000,000 kills needed!
 ? ? ?  4,500,000 kills needed!
 ? ? ?  5,000,000 kills needed!
 ? ? ?  5,500,000 kills needed!
 ? ? ?  6,000,000 kills needed!
 ? ? ?  6,500,000 kills needed!
 ? ? ?  7,000,000 kills needed!
 ? ? ?  7,500,000 kills needed!
 ? ? ?  8,000,000 kills needed!
 ? ? ?  8,500,000 kills needed!
 ? ? ?  9,000,000 kills needed!
 ? ? ?  10,000,000 kills needed!
 ? ? ?  11,000,000 kills needed!
 ? ? ?  12,500,000 kills needed!
 ? ? ?  15,000,000 kills needed!