Another tip to help increase chances of getting a c-ward is to stock pile your coffers. Instead of opening 1 per character each week try stacking for a month then have 1 character open them all in one hit. Finally got one last week after opening 16.
Recently its become apparent to me that the fusing odds have changed a tad. Never had a problem fusing from 5 to 6...1 or 2 fails "maybe". Now...suddenly in the last 2 weeks its failing upto 5 times in a row. Wards are now definitely required from rank 5.