Why Angad wears the cross......... They are the sins of lovelessness such as pride, envy, selfishness, lust for power, and impurity. The cross may also be a mental or physical affliction, or a tragic happening.
Now he is going to bear his cross.......... Bearing your cross means recognizing and repenting for your sins of apathy, lovelessness, and rebellion against the Good Spirit.
If you don't bear your cross then you will not experience the joyful renewal of life, the new beginning of love & life.
So before the union of A-K, Angad has to burn in guilt & after burning he'll change his prospective on love & life.