The Sacrifice requires a certain amount of Dragon Gene. You can collect the Dragon Genes through monsters hunting or the Training Ground. The amount of Dragon Gene is displayed as below:

　　The amount of Dragon Gene that Shadow Knights can obtain is influenced by:
　　1. Double/Multiple EXP state;
　　2. Equipment that is socketed with Sapphires;
　　3. God's Blessing;
　　4. Other items or states that bring bonus EXP.