Rummy-type Suppression and Rummy-type Suppression + are Rare, and Epic materials dropped from any of the Rummy-type Others in the game. You may have to kill them for a while until this material is found, depending on the rarity of the material that you need.
These are the Rummy that you can get these materials from and where they can be farmed:
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If playing as Yuito, the Kunad Highway—Junction is the best place to farm due to the numerous Kitchen Rummy you can exterminate. When in this area, hop on top of a bus and use your Psychokinesis to drive the bus and run over the Kitchen Rummys. Once done, teleport to a new area, then return and rinse and repeat.
If playing as Kasane, just follow the instruction for Yuito above. But instead of running over Kitchen Rummy, you drive over Buddy Rummy.
Rummy-type Suppression is used a lot in the exchanging ofgiftsto increase your bond with characters.
