If 鬼谷八荒 Tale of Immortal generated the same gross revenue on the Epic Games Store, 鬼谷工作室 would keep approximately $88,386,422 - that's $11,144,220 more than on Steam.
At this revenue level, Epic's concrete platform fee would be $11,916,330. Epic charges 0% on the first $1 million in annual per-app revenue and then 12% on the remaining amount. On GOG (30% cut), the developer would earn approximately $70,211,927.
Note: This is a hypothetical comparison. Actual sales volumes differ significantly between platforms, and Steam's larger user base typically drives substantially higher sales.