Tang Shaoyang did not use his newly acquired materials to summon new spirits but to get his current contracted spirits stronger. He knew these spirits were loyal to him. They would be on his side even if he resurrected them later on with a few exceptions.
Doombringer was a wild card. The Behemoth who sought a thrill in a battle might not stay with him.
Karoen the Void Knight had not opened up with him as well. He might leave to finish his unfinished business before he dies. He did not know even though they sometimes shared their thoughts.
Baccara was not fully on his side yet, not until he avenged her. Ammor the Sky Dragon, the Guardian of The Dragon Realm was her killer. But he did not want to fulfill that promise yet.
There were The Nirvana Alliance and The God Alliance he needed to take care of first. Now there was also The Ancient Kingdom. He did not want to add the Dragon Realm to his list.