This topic made me think it isn't that many shonen MCs that have speech tics nowadays. It's either a speech tic or a common habit they do and I don't really see it as much anymore..
It's really not new thing, right. Jotaro from JoJo Bizare Adventure had his iconic "Yare Yare Daze"(a habbit his daughter continued later on)-
Personally, I dislike it, when Natsu did it, because "I'm fired up" sounds like a stupid pun on his powers, but that's a personal thing.
Asta is shouting all the time, but I've got an headache after some time, when I've watched it. His VA, so far I know, is a newbie, and it is his second VA role. But I've enjoy the reactions of people on Youtube to this: "Boy, no need to yell everything!"-
Actually, that's something I've enjoyed the most, seeing how people who didnt read the manga, facing the anime and being surprised why this so hyped. Though, as far I can tell, many people did enjoy the first episode, several known critics were mostly mixed or disappointed. Also, the debate of "originality" in shounen seems to start again with BC's anime.
I'm not an hater of BC, I do enjoy it these days, but its beginning (and its protagonist) really bothered me, so the most exciting thing for me about the anime is, are the reactions of people who dont know anything about the manga.
Kinda disappointed that we didnt see the Opening yet. Hopefully they show it next week. Also I have the "theory" that they "cut" the whole demon attacked the kingdom and was stopped by some powerful and respected person and probably use it next week, so it won't be too similiar to Naruto(because the first episode of Naruto began with the attack of the Ninetails). Also, when they show Asta's power next week, it would be more fitting to "show" the origins of this by telling the tale of the old demon.