Bailiffs are NPCs that allow you to transfer creatures or items between your different characters. They can still be used as a deposit center if you only have one character though.
Troop Bailiff Edit
The Troop Bailiff let's you transfer creatures between your characters. And this is handy because it let's you send your Necropolis units to a Haven hero if you so wish, and vise versa. Or perhaps you have some cool event creatures you use, but not enough to have some on all you characters.
You are initially granted three unit slots in the Troop Bailiff, but you can unlock a grand total of 12. Each consecutive slot costs 499 Hero Seals. (Total cost: 4491 Hero Seals)
Artefact Bailif Edit
This NPC let's you transfer items between your characters. This is really useful if you find something on a stronger character, and need it on your weaker. Or perhaps you want all the Obelisk Shards gotten during the questline on your stronger character?
Here you are initially granted three slots as well, with a grand total ?? when all are unlocked. There slots cost 6000 Hero Seals each (Total cost: ????? Hero Seals).