Northern Light
Superstar
Amusingly, that Toronto Life article (at least for me) has a link to their article about the space where two food halls have failed in the Annex. I think the right mix in the right space might work in the Annex, but without a strong lunch or tourist crowd, it's probably hard.
The Annex space is quite close to U of T.
That's where any bread and butter lies.
You're going after the same students and faculty that need a quick bite between classes.
I think there's a market there; but price point is key as is speed of service; and your target market needs to know you exist.
The one Annex space had terrible signage and profile on its Bloor frontage.
You want a flanking patio and windows that open out on to Bloor making a real statement.
Finally, you want to find a niche within the above that's underserved in the area, if you can.