If there is a mortal race that represents all that is vile and sadistic, the goblins would commit any atrocity imaginable to obtain that distinction.
Most of the major races tend to specialize in the magic or craft they feel the most affinity for, such as elves with Wild Magic or dwarves with artifacts. The goblins, on the other hand, will use any tactic at their disposal to inflict as much misery as they can.
They especially enjoy perverting existing forms of magic into unique and twisted abominations that any rational creature would never conceive. For example, some goblins are enamored of “horrorcrafting”, a specialized form of Blood Magic they invented that allows them to transform their own bodies into hideous mutations.
Goblins are solitary creatures. They almost never work in groups, as they typically end up murdering each other in ghastly orgies of unspeakable violence. They are usually more effective in isolation, where they can direct their nihilistic tendencies towards others.