Herald is stronger than Vin. That said Willbender is stronger than herald this current moment. That'll probably change soon though. Wb is almost immune to condi, more mobility because they don't rely on energy. They have much more sustain in a team fight because they're virtues and healing. Glint heal can be big but is very short. You see a lot more Willbender's in higher elo's than you see Heralds. Just to reiterate: Herald is stronger than vin rn, but Wb is stronger than Herald. It's never been about "Can my class do that" It's always been about "What class does that better"