Old Ones was the 2nd supplement in the Palladium line: the 1e was for Palladium RPG and the 2e was for Palladium Fantasy Second Edition.
The original table of contents at File:60660-sample.pdf comes via https://www.drivethrurpg.com/product/60660/Palladium-RPG-Book-II-Old-Ones--1st-Edition-Rules?src=also_purchased
"Old Ones" is somewhat of a blanket term. Alien Intelligences such as Vampire Intelligences have been described as "Lesser Old Ones" at one point.
This moreso refers to the eight distinct "Greater Old Ones". A contrast much like that between "Greater Demon Lords" and "Lesser Demon Lords" in PF.
Pg 223 has "Syth, The Old One" described as "a lesser Old One, an ancient alien intelligence who, may not be as powerful as the famous Old Ones whose names have become words power, but is still and incredible force equal of the most powerful gods"
This is the closest to an indication of their power in 2nd edition. In saying "the magic slumber and other means of magic imprisonment are still in force and limits its current level of power to about one, one hundredth its normal level." we know it has a witch bound to it (pg 221) who casts spells at 10th level (pg 223) via the gift of union: meaning at full power, Syth while awake would be level 100, implying the GREATER old ones would be 101+.
Much like that level 50ish wolfen guy.