You can get a strong SR hero Doraemon in Solo Campaign stage 6 and At this stage, you mostly meet low level NPC in Resource Raid, you can feel free to. Guide of COZ 2 | Offensive & Defensive·Hero Selection & Base Setting. Clash of Zombies 2·Friday, December 22, Hero Selection: There are many heroes you can choose, they are divided into three grade: common, epic, legend. However, not Doraemon, Hou Yi, Hulk(Thor), Time Keeper, Athena. This is a lineup. To level it up you have to "do good" in any zombies mode. That means u have to do things benificial to the team like opening doors, reviving players, headshots.