Rein, you're lowballing Ramesseum Tentyris way too hard.
Ozymandias doesn't just have full control inside that thing--it's literally his Reality Marble. HIS territory. Not just a place he's standing on at the moment, he created the Temple, along with the reality inside and around it. Under normal circumstances, even getting into the Marble (NOT the Temple) without being let inside takes an effort that could be considered a feat in its own right.
Ozymandias is literally immortal inside that Temple of his, and King Hassan can still do it by slapping the concept of death on him AND his Temple--and then killing them both. Which is, I guarantee you, something Wiz cannot ever dream of doing unless she can nullify the reality that is Ramesseum Tentyris. Sure, she can get into the Marble, even into the Temple, but then she'd be facing hordes of sphinxes, dragons, hippogriffs and other mythical beasts AND the Temple's built-in security. All seen and controlled by Ozymandias without even having to lift a finger.
Can the enemies in the dungeon even compare to what Ozymandias has guarding his Temple? Remember, those are Phantasmal Beasts with magical and combat capabilities of their own, and not as a collective. Though, if that dungeon's enemies are in any way comparable or superior, pray tell. As of now though I stand by my opinion that Kazuma had it a lot easier than King Hassan infiltrating their respective enemy fortresses.
Also my opinion that Darkness, Aqua and Megumin are equally noticeable, albeit in different ways. My point being that if King Hassan had brought someone into the Temple and that person got detected, Gramps could still sneak through and do his thing. The poor other-person...not so much. Seems like that's beyond Kazuma's ability.
But that's not 100% relevant.
Standard Battle Assumptions. Let's see what that means.
1) Wiz doesn't even know where Gramps is, only that there's an enemy somewhere around there. Gramps is always in PC unless he consciously drops it or is attacking (and if he's attacking, Wiz is already dead), which he will NOT be doing becuase there's an enemy.
2) They start at 4 kilometres apart because of Wiz's spell range. With Presence Concealment, I'd say that's easily outside her detective capabilites, especially because she only knows there's an enemy somwhere around her. If she has feats on this, pray tell.
3) For the sake of argument let's assume she really can remove Gramp's PC. She has to start with a 4-kilometre AOE Power Null to do that. Does she do this normally?
4) If any of her arsenal has a physical form, Gramps will immediately go for concept killing. He's willing to kill and considers her an enemy to be eliminated. That's why I said it makes a difference.
5) Combined with his raw power, King Hassan near-casually flicked off high-class Divine Thaumaturgy (Excalibur Galatine) by swinging his cape at it. I ask you to present something Wiz has that can compare. Please refer to Gawain (Fate)'s page for Excalibur Galatine. Also note that Gawain was at his MOST powerful when he attacked King Hassan here.)
6) From your argument, it sounds like Wiz's sealing ability is her most effective if not only weapon that will work on Gramps. The ice seal, if she can pull it off without getting killed, is highly likely to have its concept killed. Is there something about the other sealing that I should know about?