The Reviving King understood Cairo's worry. Although he indeed gave some path to Cairo, it was not done with pure concern!
At their first meeting, the Reviving King only gave Cairo some cultivation resources. He doesn't have much hope for him
However, Cairo excelled his expectations. That makes his new expectations to be stronger than in the past
Thus, he gave Cairo a chance to attempt challenging the Tower of Ambition. He initially only expect Cairo to reach a few tens of floor
However, Cairo once again exceeded his expectation as he has the potential to clear even the 97th floor
Because of that, the Reviving King plans on using him against the First Mage. Acting out of pure care alone was different from acting based on interest
With that, the Reviving King deeply understood Cairo's worry. After all, there is a Godhood temptation between them
How can anyone easily give that up?