Need assist with mission 3.1, 3.2 and 3.3 

1. How do I remove/steal a shield buff

2. Place a heal reduction

3. Place block Debuff buff

Which heroes can do it or artifacts combination?

You need to summon certain heroes with this type of skills. Load them with accuracy and you should easy make it through. 

Yeah having the same issue.  I can’t find any characters that have the Remove Shield or Block debuff.  Any list of characters and their skills?  I accomplished the heal reduction.