According to Osho, no. Union is impossible because “darkness” (suffering/ignorance) has no substance of its own; it is only the absence of light. Light doesn’t meet darkness—it reveals it never existed. Buddhas don’t mix their light with your darkness; they awaken you to your own ever-burning light. Drop the belief ‘I am darkness’; awareness dispels suffering instantly.
Turn on your inner light of awareness and the darkness of suffering disappears—there’s nothing to fight or combine.