In addition to early-access to the game, the Ruthless expansion, & the Vi pajama skin, OC commission from Dave are available exclusively through the Skirmish campaign:
From Sharpie sketches to Golden Mementos, all the way up to one last (previously sold out) Gloria Aeterna tier.
Sharpie Sketches are available to backers in the Add-On tab, and details in the Policies tab.
Final week for the Launch Window! After that, the Sharpie Add Ons are gone.