Show the Avengers (one Hulk, one thor, one Ironman, one captain America, one doctor strange standing united in the foreground, with one Loki looming ominously in the background, holding the glowing Crystal of Chaos. The city skyline should be visible behind them, with swirling energy and sparks of light emanating from the Crystal. The Avengers should have determined expressions, ready for battle, while one Loki wears a sinister grin, showcasing the intensity of the confrontation.