Mario is full of darkness. Mario frequently uses Yoshi as a literal stepping stone and allows him to plummet to his own death, he drops Bowser into a pit of molten lava frequently. Like all the time. But perhaps Mario Kart plays host to one of the darkest concepts of all.
Like, I never thought of it this way before. You invite Koopa Troopa to a race -- let's put aside our differences for a while and enjoy some go-karting.
But surprise! The weapons you are using are literally the goddamn shell-skeletons of your brothers and sisters, who have probably been jumped upon and murdered by Mario and Luigi. What kind of sick bastard would create such a grotesque, debauched, base racing contest. Utterly brutal.
Mario, you are a terrible human being.