The base magic damage on this staff is on par with BLM's Laevateinn 85 and SCH's Tupsimati 99. Possibly worth while in replacing Magian Staves and even Elemental/Iridal/Chatoyant Staves to save inventory space.
Furthermore, this staff can be augmented to add more MAB as well as INT. Depending on the tier of Ghastly Stone used, it can have an additional MAB+30 and INT+18. It far surpasses Laevateinn and Tupsimati at level 99.
It might be nice to save on space, but it won't out-damage a fully upgraded magian staff.
(Unless you have less than 15MAB in equipment and job traits.)
If aftermath is up on blm mythic, mythic still wins and you dont need to melee to get tp casting spells gets you tp return and the aftermath stays up for 4.5 mins @ 99 just with the staff and 250% tp you have 100 MAB and 10 macc which surpasses this staff all be it probably easier to obtain than a mythic but mythic still wins in the right situations