dreammyyy
The soul cores were only made public when Huo Yuhao spread the method, after that, in DD3, the methods for forming the soul cores were already well optimized, usually they were the first on "Level 7 - Spirit Saint", the second on "Level 9 - Title Douluo", and the third on "Limit Douluo". But you don't have to be exactly on Spirit Saint to form the first Soul Core, talented soul masters can form Soul Cores sooner if they have reached the realm of a Spirit Saint (previously Title Douluo in DD2) both physically and spiritually and if density of soul power is up to it. Example: •Yun Ming in DD3 (Sea God Pavillion Master) he achieved Soul Core at Level 60. •Tang Wulin achieved Bloodline Core at level 50, Blue Silver Emperor Core at level 60, and Third Core at 90-Title Douluo