They are warped reflections of each other. Tricksters, word-weavers, beings built by stories built by lies and secrets and perverted truths. Their world is tarnished, darkened, the green something turns with envy or corruption or the inevitable damage of existing.
The difference between them, vast as the universe is vast and close as two bodies twined in sleep, trips from tongues never-trustworthy. Loki (divine, twisted, empty Loki) pours himself out through a silver voice that spins and spins and despite its efforts produces nothing of substance. The Riddler in his genius, in his madness, in all his cleverness can but contort and reflect everything he knows (the vast, impossibly vast wealth of his knowledge matched only by that ability to see truths cast beyond the umbra of the absolute), shaping and reshaping but incapable of existence in the void where language rings hollow. Side by side they lie; in love with what they are, loathing and longing for what they are not. Perhaps it is they resent each other. Together they whisper in languages similar yet incomprehensible, at once men and more than men, lovers and strangers, imitations and individuals.
They touch. Neither can discern any meaning in it.