Ask him about:
-Himself (now and his past)
-This dimension (any notable sights, hemomancy power amplifications or whatever else)
-Armok (his relation to the 2 previously mentioned and about himself)
I want my blood minions to be a good two feet taller than a normal human, muscular, and bound in cursed blood armor. And since people want cats for some reason they can be riding war tigers with their own battle armor. Spikes wouldn't hurt either.
You start asking Mathias lots of questions while you work on forming your blood minions.
"This place seems to amplify my hemomancy. Why is that and are your hemomancy powers the same as mine?"
He replies, "That is because this plane is the source of all hemomantic energy. Additionally, the vast quantities of blood provide ample raw materials for one to harness. One will be able to use all the same hemomantic powers as I with enough practice."
"Where is Armok and how are you related to him?"
He replies, "Armok created my kind to do his bidding. For millennia he ruled over us and we prospered. Overtime he became secretive and ultimately left this plane, leaving behind a single command. 'Let there be blood.' His current status is a mystery to me."
"There don't seem to be any other people here. What happened to the others of your kind?"
"Where do you think all of this blood came from?" He replies.
Your blood minion is starting to take shape but it takes all your concentration to convert the blood into the various required materials.
You complete your first blood minion a muscular humanoid clad in spiked cursed metal. He rides a massive war tiger, also clad in spiked cursed metal. Mathias notices that you have gone silent and turns to see your creation before you can make a second.
Mathias draws his flickering metal two-handed sword. He says, "I was hoping I wouldn't have to kill one so soon. So be it."
"Fun? What is this 'fun' of which one speaks?" Mathias says.
F is for friends who do stuff together: U is for you and me... Try it! Mathias: N is for anywhere and anytime at all: Down here in the deep blue blood sea!
...Play this. On the kludujalambuses.
You have never actually played the kludujalambuses before but you bet you can figure it out as you go.
You sing, "F is for friends who do stuff together." You try and guess where to press on the cursed fabric string. There are no frets so you are more than a little off. "U is for you and me. N is for anywhere and anytime at all, here in the big blood sea. Now you try Mathias"
Mathias sings, "F is for f- friends..." he stops singing as he flubs some notes on the kludujalambuse. "I don't think I can do this."
"Don't worry Mathias. You will get better and we have plenty of time to practice."