He is very weak compared to a world god. That's why he had to expose some of the secrets of Legion or the sage wouldn't have taken him seriously. In fact, the sage might have decided to hunt him down immediately. There wouldn't have been any negotiations. The sage could send thousands of Origin gods after him and they will kill him again and again until his mind actually fractures from the deaths.
The sage is scheming and pragmatic at all times. Soverick had to avoid the fate of being hunted down by showing the sage how difficult it will be to end him. The sage could end him but he decided not to do so because it will take a lot of resources.
And antagonizing Soverick means antagonizing whatever entity or entities Soverick is. The plane will take the brunt of the clash between the two of them. The first sage certainly doesn't want anything bad to happen to the plane so that its performance during the era of conquest will not be hindered.
The sage weighed the option and decided that the cost of trying to eliminate Soverick it is not worth it. So the sage gave him payment that is less than what it will cost to send immortal mercenaries after him. That's why they negotiated his compensation and reward at all.
He died because of the Sage's scheme and it was hurtful. He would very much like to have his revenge. But the sage gave him a warning. The warning is that world gods know how to wait and plan for the long term. The sage even used the realm tree's situation as a warning. It is to tell him that if he is to go on a rampage now, he better be prepared for the future consequences.
The fact is that he can disregard that warning and go on a rampage. He can do that either because of foolish anger or because of confidence in the strength he will have in the future. If he did, he might get away with it or he might become like the realm lord who will become beset on all sides by enemies in his moment of need. Either way, he will not be able to get anything from the sage if he went on a rampage in the plane and harmed the Sage's benefit.
The story of the realm lord is both a warning and advice. He died and nothing can change that. He could go for short-term benefits like destroying a lot of infrastructure in the plane and killing people thereby gaining himself several world gods and the racial council of the Virut plane as enemies. Or he could focus on the long-term benefits by negotiating with his killer and getting two out of the fragments of a realm heart for his death.
He chose longer-term benefits. It is the choice that will make his death worth something and will also help Legion. He is a pragmatic person who makes decisions using logic instead of emotions. The benefits outweigh the costs so he will lay low and accept the insult. Besides, revenge against the sage is not ruled out yet. He just has to be patient and farsighted.
The opinion of the weak doesn't matter anyway. There is no justice for the weak. He is angry but it is of no use because he is weak. Mindless anger will only hold him back for now. He can return to the anger when he is strong enough. Then he will have the right opportunity to exact the revenge that he deserves.
"I wonder what will happen next. Either way, I have to be prepared." He said as he looked upwards in the direction of the void. "It is not over yet."
He made good with the sage and he settled the matter of his death and compensation for his efforts in the competition. But that doesn't mean that he is in the clear with the first sage. That doesn't mean he is safe yet.
The process of negotiation was fraught with dangers and pitfalls. But the danger hasn't ended yet. The sage didn't make any oath not to come after him again and he didn't force the sage to make one because he doesn't have any leverage to do so.
You can't make a smart person do something beneficial to you willingly if there's nothing for them to gain from it. The only way to achieve that is to force them to do it because they won't do it willingly. He would like to be safe from the sage but that's just what he wants. He can't make the sage promise to stay away from him like the time he made the sage promise to keep him safe during the competition.
The sage had to promise him back then so that he will attend the competition. Even that promise didn't work out so well. It didn't prevent the sage from finding a way to get rid of him. His current situation is more perilous. Back then, he still had some use. Right now, he has been discarded and much worse is that he has become a thorn in the side of the first sage. Not having leverage is just the tip of the iceberg of his problems.
In fact, he didn't have any leverage in the entire negotiation apart from the fact that he could resurrect. That's why he couldn't demand for anything. The best thing he could do is retain his position as a sage of the plane. Which he managed to smuggle into his oath. That will prevent the sage from turning the entire plane against him and openly going after his life. That just leaves the hidden and subtle approach.
One such subtle approach is asking him to come to the void to receive the things he asked for. That means he will be able to finally meet the first sage face to face and not through a meeting of the minds. Some will be ecstatic about the opportunity to meet a world god who is also a hero of the race. But he can't be ecstatic because it is a good opportunity for the first sage to freeze him.