Next we need some chunks of magmite. See these Eldritch Charges? Place one of them on a Spawn of Centius before he is destroyed and it will shatter him into pieces. Then all you need to do is pick up the Magmite Shards.
You've gathered the Magmite Shards, I see. The magic in those are key to creating the Titanbane. It's the only hope you have of defeating Centius.