I'm Already a Martial Saint, and You Say Demons Are Invading?

[Apocalypse] [Monsters] [Overpowered Protagonist] [Passionate Martial Arts] Year Three of the Monster Apocalypse! I've finished my seclusion! Bad news: My luxurious estate is now a ruin, and the world has ended?! Monsters everywhere?! Good news: The Ultimate Martial Arts System has awakened! From the start, I inherit a century of cultivation and rise straight to the rank of Martial Saint, the strongest in the mortal world! My blood and qi surge like an ocean! My imperial astral energy dominates heaven and earth! A mere thought can change the weather! Me, Su Zhe, invincible in this age?! I only wanted to keep a low profile and enjoy myself, but the moment I step outside, I find monsters running rampant and the city fallen?! What the hell is going on! Even worse, the shadow of the "beast-fur hand" that killed the previous Martial Saint has already fallen over all of Blue Star! Even a peak Martial Saint is no more than a slightly stronger ant before that unknown being?! System mission: Kill the owner of that hand! Are you kidding me? I'll die! "You piece of junk System! Are you messing with me?!" Luckily, the Daily Sign-In System activates! I've already accumulated over 1,000 beginner sign-ins! [Ding! You can combine them into 100 intermediate or 10 advanced sign-ins!] Martial arts manuals! Divine weapons! Character cards! Even resurrection, time travel, and plucking the strings of fate?! Anything is possible! "So you're the black-furred hand? Just you wait! First, I'll lie low and build myself up!" But just as I try to keep a low profile, a blind Ninth-Rank Bone-Spike Demon shows up to provoke me? It even wants to eat me?! "You're just a puny monster, not even fit to get stuck between my teeth! Perfect, let's see if one punch from this Martial Saint can blast through the atmosphere!" "The light of a fist. I saw a peerlessly invincible fist-light." "Blood and qi. I saw blood and qi churning the stars and rivers."