New Duchess and Revenant player who has a few questions about them

**Duchess:**

1. What weapons can I use with Duchess besides daggers so I can do meaningful damage?

2. How do I get staffs and starlight shards so I can take advantage of her good int scaling?

**Revenant:**

1. Where do I find seals and starlight shards?

2. What are her summons good at? And is there a way to make them respawn faster once they are defeated?

3. Is there any faith weapons she can use as a backup?