Dungeon Invasion, Upgrade the S-Level Summoned Beast at the Beginning

Unfortunately, Zhou Cheng traveled through time. Seeing that his life had directly changed from a moderately prosperous life to a catastrophic life, Zhou Cheng felt a little helpless. However, the clear voice in his mind immediately eliminated his helplessness. "One-click upgrade system can upgrade summoned beasts to the highest level!" "Oh haha, not bad!" ... "Do you know why there is S level above A level? A is obviously the first letter, because S level and above means that he can rewrite the rules. Therefore, if you encounter an S level monster, don't do anything and wait for death." These are the words from an old man who is experienced in underground cities, reminding people of the horror of underground cities. "S-level, what about it?" Zhou Cheng pointed at his soft and supple mount. "Are S-class monsters scary? It's too slow for me to move!" This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.