
is he an antagonist no, although "bad person" is subjective.
he still works under the devil hunters and imo is the epitome of being their dog. not saying he has no will but we never see him stir away from what hes told to do, eg having to kill asa before she turns the room into a weapon even though asa and yoshida(octo boy) were on decent terms after their talk about her relationship with denji and the consequences of harming him. yoshidas main mission from the devil hunters is to protect denji, denji wanted to live a normal life w the control devil so thats what yoshida is for. he protects him hence the stalking and makes sure his identity isnt revealed. although for asa fans, (which is me ig but i dont really care for picking sides) uve peobably seen them hate on him for trying to kill her. despite asa also being our protagonist, shes also a antagonist/villain since shes has the war devil yoru and is currently going ham rn as seen in the latest chapter of her being happy the world is going to shit. so yoshida going against her doesnt make him a bad guy ppl just dont want asa to die. some other people shit on yoshida for being "bad at his job" bc he cant control denji (hes been keeping him safe so far so honestly its a weak point but its mainly a joke so eh) or how he tries to negotiate with denji on whether he lives a normal life w nayuta or be chainsawman without her which is kinda of cruel but then again its all for the sake of denji and keepinf the control devil from going bad like makima.
soz for long para i trier fittinf different perspectives but anyways long story short hes not bad imo
i dont get why people r finding this confusing its not that hard to understand imo. anyways i cant wsit for death devil reveal