Ipslore the Red |
You can choose between an ib and ka soul stone if you're a caster. If you're a martial you automatically get ka. If you pick ib you get spellcasting progression but lose greater and master ka stone. If you pick ka stone, you get Toughness all the time and full BAB from your Living Monolith levels when you're using enlarge person from the ka stone.
Note that "an ancient language" in d20pfsrd's prerequisites and "Ancient Osiriani" in Nethys' are the same. d20pfsrd has to remove Paizo's intellectual property, like the name "Ancient Osirion".
I believe Archives of Nethys updated quite recently, as the text of Living Monolith now looks different.
Before, it was just ka stone, martials lost BAB even when enlarged, and casties lost spellcasitng progression, as I recall.