Fire is a path available from Vamos by default, although he can only ascend Fire weapons from +5 to +6 after he is given the Large Flame Ember. To create a Fire weapon, the player must have Green Titanite Shards, a standard weapon +5, and the requisite souls. Further upgrading from Fire +5 and on requires Red Titanite Chunks to +9 and a Red Titanite Slab for +10.
The Fire upgrade path adds Fire Damage to all weapons, while removing all stat scaling bonuses. This makes Fire a good choice for lower level players, although the removal of scaling makes it a poor choice for those with high stats.
The Fire path tends to deal less damage than the Lightning Path as most armor and shields have higher Flame Defense than Lightning Defense. Fire is superior to Chaos in terms of damage if the player has low liquid humanity, but Chaos ultimately deals more damage than Fire as the player's humanity approaches 10.