Abandoned as R-Rank, I Became an SSR: Why the Tears?

+++"How unlucky!" "An R-rank contracted spirit, wasting my 180-pull pity!" "A useless character like you, are you even worthy of being contracted by me?" Spirit Contractor Jiang Li's face turned ashen, and she furiously canceled the contract, saying viciously, "Trash character, just wait to disappear!" Xia Yuan transmigrated into the lowest-tier R-rank character in the card pool, and as soon as he was drawn, he was bombarded with scolding. He was angered to the point of laughter—he had awakened the Ever-Changing Battle Power System! As long as he was contracted, he could transform into an SSR ceiling-level battle power character! This woman is truly blind as a bat. However, if not contracted, as a card pool character he would dissipate and be annihilated, unable to exist in the world. The entire Spirit Contractor Academy, no one wanted to contract an R-rank character. Just when Xia Yuan was somewhat desperate, the campus belle among the new students with the strongest spiritual power, Mo Shiyu, stepped forward and contracted him! From then on, an absolutely overpowered ever-changing SSR was born. Transform into Satoru Gojo, Limitless Cursed Technique, Domain Expansion, Cursed Technique "Azure", Hollow Technique "Purple"! Transform into Gilgamesh, with Chains of Heaven, Gate of Babylon, and Enuma Elish! Transform into Uchiha Madara, with skills like Planetary Devastation, Susano'o, Tengai Shinsei...! One after another, ceiling-level battle power characters make their grand entrance, who dares contend? Watching that R card she had discarded become the unrivaled ever-changing overpowered SSR, Jiang Li's guts turned green with regret, "He is the card pool character I drew, give him back to me!" Mo Shiyu gave a slight smile, "A bargain I picked up with my own skill, and you still want me to return it?"