I'm using Mavarro essentially as a backup cleric (alongside Drelm), and he's pretty useful. I'm putting him on locations with Ahmotep because even though you will be rolling d10s, the lack of a bonus (before you get those skill feats) is rather iffy. I think Mavarro's best card is the Blessing of the Elements, as it has the most skills available to you. Also, they allows you to give you extra explores and help out on other skill checks. Adding the fact that I have the two weapon staves avialiable, he's able to do work, and is fairly consistent, yet stays fluid.