This is a fun battle.
Attack Potency
So Mob's raw psychic prowess is such that he can counteract Simurgh's only....real?...offensive abilities, that of telekinetically tossing debris (in the form of buildings at times, but still debris).
The Simurgh won't be able to do terribly much to Mob's psyche I don't believe with her passive psychic scream, and with the planet being devoid of life, no biological-based Rube Goldberg-esque effects can take place or be put into action, arguably her greatest offensive ability.
Mob has the advantage here
Durability
Okay obviously Simurgh has this one in spades. But, as noted, this battle is specifically in-character, so if Mob gets to 100% or ???% he can and will put her into submission and force a retreat.
As for Mob, he doesn't even rely quite heavily on his TK for his durability and can take buildings being thrown at him reasonably, and his TK is pretty well above Simurgh's in-character usage, so he can take her attacks and dish out his own.
I can't believe my statement, but Mob has the advantage here
Hax
This one, The Simurgh ought to hands-down win with her sheer variety. Precog, vast Future Sight, her passive Mental Manipulation.
Unfortunately, Mob does indeed have Resistance to Mental Manipulation so.....
The only point people might bring to the table is that Simurgh can power-copy.
In canon, she has only ever copied Tinkers' powers explicitly. She is stated to be able to copy the perception powers of Thinkers, but not their entire powerset, so the argument of 'Simurgh copies Mob GG' doesn't apply per canon imho.
Further, Mob himself has the ability to absorb/reflect Espers' powers, so it would be a moot point to argue once he got serious.
Essentially a tie
Speed
Speed not equalized in a thread involving Worm characters, Dargoo confirmed for anti-Worm bias
I don't believe this needs engaged much at all.
Mob holds vast superiority in the speed front to the point it's laughable, both in base and once he gets serious. If Simurgh pushes him, Mob becomes orders of magnitude faster and the poor Endbringer just won't be able to keep up, even with her Future Sight. Seeing a blast of TK coming means nothing if you can't react to it, after all.
Mob holds a laughable advantage
Conclusion
Simurgh has her options pretty limited here. Her 14-year-old adversary possesses a similar level of TK, and her psychic screams will quickly turn to ones of frustration when she realizes they don't do much to him.
Being in-character and speed unequal lets Mob hold some severe advantages.
Mob wouldn't stomp, remotely, but unless Simurgh foresees him going to 100% and sets up a quite elaborate trap using Brockton Bay in a way that only Wildbow could come up with, I don't see him losing easily.
Vote for Mob