>how can Doom be a threat after Galactus
Aside from stealing the power of galactus (twice), the beyonds powers, turning ultron into his own personal bodyguard, time travel, dark sorcery and enough knowlege to be a candidate for earth's "sorcerer supreme", pacts with demonic and cosmic forces, and super science that easily rivals reed richards?

In the MCU I expect Doom will fill the role of norman osborn in corrupting the sentry and using the void to strike down his enemies. But aside from that just imagine a smarter iron man combined with dr strange and exotic stolen weaponry that rivals an infinity stone. He will be a massive threat.