The one who received Thanos in the restaurant was a Doombot. The real Doom of 40K had run into a bit of trouble caused by the Timeline.
Although Doctor Strange of Earth-616 was also a member of the Illuminati, he had ultimately gone down the same path as Namor.
He summoned the Old Ones who existed beyond the heavens, made a deal with them for power, then used time to return to ancient days and secretly establish a cult.
While the Black Swans under Doom's command eliminated universe after universe by assassinating or abducting Molecule Men from different Parallel Worlds,
Doctor Strange, wearing a golden One-Eyed Alien helmet, was doing something similar with his followers.
Both sides had arrangements made through the Timeline and forces accumulated over time, and now they were doing the same thing. It was inevitable that they would encounter each other and clash in secret time and again.
At this moment, Doctor Strange found the headquarters Doom had prepared for the Black Swans: the Multiversal Library, created by the Beyonders.
"Did Deathstroke foresee even this?"
Doom, who had teleported into the Third Dimension, prepared to receive his guest in the depths of the library. Before him stood a purple pillar of light that reached from heaven to earth, erupting from a vortex like the mouth of a gigantic well. Deep within it, a swirling Nebula could vaguely be seen. It was the complete form of the multiverse in its most chaotic state.
At first, it had been an egg. The Big Bang gave it birth, creating endless possibilities and chaos.
There was nothing worth looking at. Stare at it too long, and it would drive anyone mad.
If Deathstroke had been here, he would have said that this enormous well mouth somewhat resembled the chamber containing