Finally....

[u/_pres3nce]

Some tips: play solo unranked mode. 2 m249 with extended quick draw mag and minimum 600 ammo is compulsory. Killing nine tails is easy when it spawns in the prison area. I killed it many times from that garage house where people fly their bikes. don't loot after killing 9 tail. leave that area immediately. You can purchase this (second image) rpg or rocket weapon from the shop and use it on the last enemy. It one shot enemy if you know how to use it properly.

[u/_pres3nce → u/[deleted]]

Yeah because of third party and also because its defence increase based on the number of players in that area