Dunno, "Molybdenum/Vanadium steel" at Rc63 could be one of the VG series steels, it could be Vascowear or it could be Aogami Hitachi blue. There's no way to know if it's a super hard stainless or super hard carbon core surrounded by soft stainless for toughness and ductility.
Anybody who has more experience with Blazen care to answer this part of the question?
Either way, you've got a seriously hard core steel surrounded by softer stainless. That's a good thing. Whether or not that core takes a patina* is largely irrelevant because it's a small portion of the overall blade width and easy to take care of. So, yeah, use it on lemons. Go nuts.
* Patina has a soft "a," by the way, emphasis on the first syllable -- PAT (like CAT) - in (like kin) - uh (like, um, uh) PAT-in-uh.
It's not puh-TEEN-uh or, god help us, puh-TĪN-uh, with a long "i" rhyming with vagina. I heard this once at an antiques show and about slugged the person who said it.