If not the power to change things or to transcend them altogether through the achievement of some immaterial spiritual state, what then is the way advocated by Zhuangzi? On the verge of death, Zhuangzi has Ziyu say, "If you are content with the time, and if you dwell in what is fitting, then anger and joy will be unable to enter you. This is what of old was called 'untying the bonds'. If you are unable to untie them yourself, then you will be bound by things. But things cannot ultimately overcome Heaven. What is there for me to detest?" (Zhuangzi 6; Puett)
If one can be "content" in the givens of existence, whether contingent (accidental, unnecessary) or 'inevitable' (necessary), and "fit" comfortably within them, then one has "untied the bonds" and realized a freedom in their midst. One is not thereby freed from their physical effects, but from their potential affect. Indeed, one is not freed from them, but because of and through them. "Every enslavement is also an ennobling." (2:41; Ziporyn)
Let us remember that we too are "things"; every bit of us. We are freed from ourselves only because we are and remain selves, things. Nothing can "overcome Heaven". What is Heaven? It is not something other than everything. It is The Great Clump. Nothing can overcome Heaven because everything is heavenly. Nothing can overcome Reality because everything is reality. Harmonizing with one's reality is harmonizing with Reality.
Are we then not allowed to experience anger and joy? This very same Ziyu, let us remember, just had a good laugh with his buddies in their agreement that nothingness is our head, life our spine, and death our ass. No, there is anger and joy and then again there is anger and joy. There is the joy that is contingent on circumstances, and the joy that depends on no circumstance. There is anger that is an expression of our own discontent, and anger at what brings discontent to others. One dyad is a cause of disharmony, the other an expression of harmony.
You can check out Scott's writings on Zhuangzi here.