Hi! You’ve said that you consider Dr Doom to be a better villain than Thanos. Can you elaborate on why that is? because I’ve gotten kinda tired of the willfully blind shrieking egomaniac, and his ANAD personality fells like a breath of fresh air.

There are two things I dislike about Thanos:

1. Thanos’ nihilism is something I stopped finding interesting in high school, so I find his personality a bit juvenile and un-engaging. 
2. Because of his obsession, there’s only a few stories where Thanos works – pretty much only space/cosmic stuff. And while I like Infinity Gauntlet and Infinity War better than most modern Marvel events, you run the risk of repetition. 

By contrast, I think Doom is far more flexible from a writerly perspective:

• Since he’s into magic and technology, you can do stories where he walks into hell to try to rescue his mother’s soul from Mephisto (Triumph and Torment is one of my favorite mini-series, and features some great Mike Mignola art), or stories where he builds a time machine to steal Blackbeard’s treasure. And it means he can fight a broad range of heroes, from Ghost Rider to Iron Man. 
• Because of his Byronic/Noble Demon personality, you can also do a range of tones and moods as well. Doom works great in comedy, because his hamminess, dignity, and ego make him a perfect target for Squirrel Girl or Spiderman or the like. But those same character traits make him work for high drama (see the aforementioned Triumph and Torment) and you can always use the ol’ Doombots to explain the difference. 
• Finally, his egomania is actually quite useful from a storytelling perspective. How do you reset the world after the villain’s conquered it? Because Doctor Doom cares far more about proving his superiority than world domination for its own sake, he goes back to Latveria and tells the heroes to put up more of a challenge this time. How do you keep coming up with reasons for the hero and villain to fight? Because Doctor Doom loves vendettas so much, he doesn’t need a reason beyond showing them who’s best or revenging himself for a personal slight. 

A great example of this is X-Men #145-147, where Doctor Doom fights the X-Men in his castle in…upstate New York, because of course Doctor Doom has a castle in upstate New York filled with flunkies with Brooklyn accents. He beats the whole team, does the Bond villain deathtrap thing with them; he gets all swoony over Storm and invites her to dinner before turning her into a living statue; and he palls around with Arcade, because a clown like him needs a straight man like Doom. 

You just couldn’t do a comic like that with Thanos, because he doesn’t work at that scale or those tones.