Caprinicus' spell will work differently to the way it is ordered.
Caprinicus may Steal Attack/Magic before dealing damage, rather than do exactly what the Spell description says: "Deal X Damage to an enemy...Steal 4 attack and convert it into Magic."
This may happen when the Spell is cast if the Spell is going to kill the enemy. This is not a bug: the game team has designed this to avoid issues with the Spell. If the enemy were to die first from the initial "Deal X damage" then Caprinicus would not be able to Steal magic as the enemy is dead. The game is designed to help you get the full benefit of the Spell.
Troops that deal damage and Steal Magic will also work in the same way, such as Amira.
NOTE: The game team does not plan to change how this Spell is ordered or written.