Fortunately, the blue sun's destructive properties were no longer in the lead, and the three sources weren't completely extinguished. But, in all their metaphysical glory, the three sources melted and mixed into a puddle, which, due to the searing heat, was refined, blended, and purged of impurities and unnecessaries.
It was an unlikely and unexpected event that would have never occurred if anything had been different.
Like the Stone of Wisdom, when the three sources had been completely refined and transformed into something new, something greater than the simple combination of Will, mana, and vitality, the Smelting Furnace expelled it and focused on taming the blue sun.
The new source escaped the seal put on the Smelting Furnace's soul shard and joined the rest of Ackster's soul inside the sphere created by the liquid Stone of Wisdom. At first, the swiveling lump of the new source floated separately from the Stone of Wisdom and the pile of soul shards.