Golden Core in Three Years, Nascent Soul in Five: Speedrunning Immortality

[Fast-paced, immensely satisfying + speedrun cultivation + no suppressed cultivation levels + powerful expert reborn + misaligned System + multiple female leads] Xu Muge, who had been in a vegetative state, had a very long dream. In it, he spent a thousand years in the cultivation world, cultivating to the middle stage of Deity Transformation. Just as he was preparing to head to the Spirit Realm, the dream ended. Then he suddenly discovered that he had transmigrated into the cultivation world from his dream, back to the moment just after joining a sect and before he was about to begin cultivating. Xu Muge was ready to make his mark on the world when, after being bullied by a senior brother, he became bound to the Good-for-Nothing's Rise to Power System. System: [Host, you come from humble origins and have average talent. The System can help you turn your life around, rise to prominence, and reach the pinnacle of success.] Xu Muge: "I have the complete memories of a Deity Transformation Celestial Lord. That's practically the same as a Deity Transformation Celestial Lord being reborn. Are you sure you haven't bound yourself to the wrong person?" System: [Confirmed.] Xu Muge: "Fine, fine, fine. In that case, let's set a goal: Foundation Establishment in one year, Golden Core in three, Nascent Soul in five. Speedrun cultivation!" Every time the System issued a mission, it offered three difficulty levels. The higher the difficulty, the better the rewards. But for Xu Muge, with his memories from his previous life, even the hardest missions were achievable. A few years later, the outer disciples who had joined the sect alongside Xu Muge finally broke through to the middle stage of Qi Refining, while Xu Muge was already preparing to undergo tribulation and ascend.