Apr 28, 2021· Information. The investment system for Guild Dungeons was implemented on the main servers on August 7th, 2012. Guilds owning a castle may invest in their castle using the Paw Merchant located in their castle.; Players not in a guild may invest in the dungeons realms by talking to the Paw Merchant located in each realm.; There are 2 ways to invest, with Zeny or with items.