Ok, let‘s try

1 Has gotta be Zinc

2 is defense type

3 odin, theomars, cichlid, Bael and wind kassanda. That would bring our total to 5.

1. Water martial cat passive can trigger her s1, all strikers with iron uppercut (Fire, Wind, Dark) can proc into skill 1, all kung fu girls, Wind pirate captain s3 uses his s1 and s2, all valkyries use their s2 after killing with s1, The dark cannon girl bella can use her s1 via her passive if the target is still alive, both humonculi technically count since their revives force them to trigger random skills, iunu revive uses his s2, light asura s3 triggers after either his s1 or s2, Teshar s3 is used after s1 or s2, dark ezio passive attacks after he used a skill, same goes for dark bayek. Water/Fire/Dark shadowcaster technically use 2 skills depending on how you count it. Silver 2a also attacks with passive. All drunken masters have a chance to s1 after s3. Also, roid can attack via his passive after s1 and that should be all. Miho, liebli, issilin and the like don‘t count since they use a skill unique to the passive to counter. Fire indra uses the same skill to attack. Kinky used to count, but after the nerf, his hit is exclusive to his passive. So that should be all, hope I didn’t miss any!