Any novel about revenge troupe that has netorare / netori. With mc mainly dissapointed to how worlds going on. Reincarnated and Summoning is welcomed. Active translation. If it is in active, at least have 40 chapter translated. I don't mind royal road or qidian. I don't really mind harem, but prefer slow romance. All in all, anti hero mc but not overly scumbag.
I recommend Nidome no Yuusha, Kaifuku Jutsushi no Yarinaoshi ~ Sokushi Mahou to Skill Copy no Choetsu Heal and maybe Sairin Yuusha no Fukushuu Hanashi
Doesn't really fit the first part of your criteria, but the greatest antihero that comes to mind is Leylin from Warlock of the Magus World.
The MC in that one is retarded. He willingly gets raped (by men) again to get a justification to get revenge. He likes suffering to get revenge rather than preventing catastrophes and getting revenge anyway.
I have done reading nidome and Sairin Yuusha. Choetsu heal too, and dropped it. Not my cup of coffee, anyway. Thanks.
If you're looling for anti hero then all of get lost novels hve the best anti hero theme. Try Way of the Devil Mystical Journey