Goblin Slayer

Goblin Slayer (Japanese: ゴブリンスレイヤー Hepburn: Goburin Sureiyā) is a Japanese Dark Fantasy Light Novel series written by Kumo Kagyu and illustrated by Noboru Kannatuki., which began serialization in 2016. It has two manga series, three Drama CD's, a side-story named Year One (both in manga and novel format) and a 13-episode TV anime series released in 2018. It started as a sort-of online textboard roleplay combined with ASCII artwork, which was later rewritten into a novel format and sent to some writing contests; it was picked uo by the GA Bunko publishing label, and then one thing led to another...

The series itself begins in a terrible note, story-wise. A rookie party formed by a Fighter, a Female Wizard, a Warrior and a Priestess, all of them at quite the low power/experience rank, decided to go into a nest of goblins to try wiping them out and rescuing their prisoners. However, due to their lack of preparation, the group is horrifyingly overwhelmed: Warrior is literally torn apart, Fighter is captured and gang raped, Wizard is fatally wounded, and Priestess is all but in defense against the goblins themselves. Suddenly, however, a stranger decked in full-body armor shows up and saves Priestess, helps her rescue the still-living Fighter, gives Wizard a Mercy Kill at her request and completely annihilates all the Goblins and Hobgoblins there.

Priestess learns that the man is the Goblin Slayer, an adventurer whose one and only goal in life is to eradicate all kinds of Goblins. Feeling that she owes him her life and that she still wants to go further in adventures, she becomes Goblin Slayer's partner and keeps travelling with him. Eventually, the two form a more stable party with other travelers (a High-Elf Archer, a Dwarf, and a Lizard Priest) and keep on fighting, exploring the dangerous world, and exterminating Goblins and other menaces.

Tropes used in Goblin Slayer include:

Blood Knight: Goblin Slayer comments that after so much time killing goblins he may as well doing it because it feels good to fight and kill them.
The Comically Serious: The title character is prone to give straight-forward Mathematician's Answers, is almost completely single-minded in killing goblins and often answers with a straight "Yes"/"No", or "Is that so?"/"I see". The result is this.
Everyone Calls Him "Barkeep": Everyone, no proper names are given.
Fan Disservice: The Wizard's chest bouncing? Good. Bouncing because she is struggling with a goblin that seeks to beat her up and then rape her? Not so good.
The Faceless: In-universe, most people never saw Goblin Slayer's face since he never removes his helmet. At the end of Volume 1,Priestess asks if she can see his face and the title character removes his helmet without any problem in public.
Five Races: Minus the Gnomes (or rather they are elemental spirits), plus Lizardmen. Also, the Halflings are called "Rhea" and instead of insistence on walking barefoot may have mild graphomania (at least according to Arc Mage, «Rheas, you can't stop them from writing»).
Human Shield: At the climax of Volume 1, a group of goblins uses human hostages as shields, knowing humans aren't likely to kill other humans to reach an enemy. Also, in Year One a hobgoblin tried to use a girl like a shield. Goblin Slayer noted that the good thing is, goblins have no clue of how to use a shield in the first place, so this doesn't particularly hinders killing the hob.
Oblivious to Love: In-universe, this is the witch's opinion about both Goblin Slayer and Priestess.
Older Than They Look: The High Elf Archer looks like a young adult at best, but it is actually 2000 years old.
Rat Stomp: One of the easiest jobs for adventures consists in taking on giant rats.
Revenge: Goblin Slayer's initial motivation to kill goblins was to avenge his family. As time goes on,however, it takes the shape of a psychological obsession(he only does that,even knowing there may be more important jobs which may save as many or even more lives as killing goblins do), and he says to Guild Girl in Volume 1 he is beginning to enjoy it.
Skewed Priorities: Goblin Slayer dismisses a quest to save the world from an army of demons because goblins attacking villages are somehow more important. However, soon he lets it slips why he does that: there's so many Evil Overlords appearing and then being defeated that he feels there's no consequences if he ignores such tasks in favour of hunting goblins, an activity that attracts well less attention from adventurers, downplaying the trope. Also, there are people who specialize in fighting demons, while he is the guy who kills goblins (and is good at this)… though whenever it turned out there's someone else using the goblins as cheap minions, he was resourceful enough to handle that, too.
Supporting Protagonist: Most of what happens in the story is followed through the eyes of Priestess instead of the title character.
Training From Hell: Goblin Slayer's master was an old, tough and constantly irritated ~~halfling~~ Rhea — more or less their world's version of Gollum (he even asked what's in his pocketses once).
The World Is Always Doomed: In Volume 1, Goblin Slayer offhands mentions a demon lord have awakened ten years ago when it's told one is doing the same thing now, basically saying there's no point for him to care about such threats when they're always happening and are always stopped by someone else.
Zerg Rush: The goblins are generally weak, but they attack in numbers to compensate for their individual weakness.