I find it strange how Titamon, who has all the attributes of a Big Bad, is often just a general for someone or just kinda there

I mean, their number changed several times over the years, and the last one when Jesmon added to the team.

the malevolent Fist/ Boltoboutamon

While Boltboutamon himself has no will or consciousness of his own, he is controlled by Malevolent Fist, and this entity is basically Dark Homeostasis. This entity is so evil that it wanted to replace darkness itself with a new, even more evil darkness.

This thing is somehow capable of distorting Positive things like Progress and friendship and using them for its own interests.

Just read these quote, and you'll understand what I mean.

My... no, OUR goal is to swallow up all of this old darkness and mix it together into a new dark power. You humans know this well, don't you? The newest products always perform better. The old is just a foundation for the new. Such is it's purpose. Oh, don't you look puzzled? I think you'll understand you see my power in action. I made this body first so that no one could escape me in this world, after all. Though I did just use whatever materials I had. There's certainly room for improvement. Now, let's begin the banquet of blood, the feast of madness! „

The power I borrowed from you and your friends... What was it called? Ah, yes, "Bond.It took some effort to make it useful, I admit But look! It's reversed; I've inverted the very principle behind it! Now it fills me with power instead. I call it a "Dark Bond." What do you think of that name?"