Shadow Realm works similar to Shadow Walk: When cast while attacking, you automatically stop attacking, as to not waste the damage boosted attack out of Shadow Realm.

However, there is one issue. When you give Dark Willow and attack order so she first has to move closer to the target, and then cast Shadow Realm while she is moving closer, she will instantly attack and waste the spell completely.

As a comparison, when the same is done with Shadow Blade, the hero just moves within attack range and then stops there, not attacking the target.

Shadow Realm should do the same. Instead of immediately attacking, she should continue walking towards the target until within default attack range, and then you have to give an attack order again, to use the damage boosted attack properly.