Florentius Baenius is quite outspoken and loud in his interactions with others. Despite being a priest, he is no stranger to making wild claims about his prowess in combat. Supposedly Arkay, the god of burials and funeral rites, converses with him regularly.
Florentius Baenius is rescued from imprisonment in Ruunvald in the quest Bolstering The Ranks. He then agrees to return to Fort Dawnguard and aid the cause, which is where the Dragonborn first witnesses Arkay and Florentius interacting.
Florentius asks the Dragonborn to retrieve an ancient relic that once belonged to the Dawnguard of old. The artifact must be retrieved from a radiant location. This quest is offered up to three times, each time for a different item.
When asked about the old Dawnguard, he has quite a negative opinion and remarks that they were not the noble defenders that people make them out to be. He believes they were no strangers to looting and pillaging homes and were even said to have hidden caches that bore their sigil. Supposedly, these caches can be opened using Sun Fire. Although these ancient caches no longer exist, the modern day Dawnguard employ a similar method of hiding supply caches for members out in the field.
Do you know anything about the old Dawnguard?:"Oh, I've read a few things. Heard a few more things. Arkay's told me a bit as well. The story they'd like you to believe is that they were such a noble bunch, doing the honorable thing and saving lives. Only I hear that's not quite how it happened. Secret organization, you see. No one to blame when homes are broken into, things stolen. Heard they'd go on midnight raids, pillaging and looting, and then stash the spoils somewhere, guarded by their sigil. Arkay tells me the Sun Fire spell can break open those caches, but I've never found one. I think he might be lying to me."
"It is my sworn duty to see Arkay's wrath delivered to all the undead. It's usually a good bit of fun, too."
"Arkay's been watching over me for years now. He says he's not too sure about you yet, though."
"Don't you worry about me. I've been through worse. I'll come out of this just fine."
"Arkay be with you, my friend."
"Arkay bless you, friend."
"Potions my friend, potion! Possibly some spells. Maybe some other things I've forgotten about. Actually I'm not sure. Let's see, shall we?" - When trading.
"Look, I'll be honest with you. I have no idea. But I'm sure we can find something worth your time." - When trading.
"A noble cause, Arkay likes the idea very much, so I'm happy to help." - When asking for training.
Various members of the Dawnguard don't know if he really does speak to Arkay or not "I've never heard of a Divine directly speaking to someone before...""...Maybe we're just all a bit crazy to be here".
Whether or not Florentius actually converses with Arkay is up to debate. Aedra are not recorded to have regular direct interactions with mortals, but Florentius regularly displays knowledge and facts that couldn't have been obtained through conventional means.
PC 360 After completing the main quest and going around asking Dawnguard NPC's if there is anything one can do to help, they will all say, "speak with Florentius, he has something for you." When speaking with him the dialogue option is not open to help. Often, this can be the result of already having a quest given by Florentius.