The incantation time of the Enchanter, Trance and Invocation abilities are all longer than the corresponding Boon/Affinity/Pact spells and the effect duration is shorter, however they are more powerful an enhancement than the corresponding Boon, Affinity or Pact. Additionally, having all four party members' weapons enchanted accounts for a great deal of fast damage, and better assurance of useful debilitations, such as setting a Griffin's wings aflame. It also ensures the Mystic Knight has the element they need to modify spells like Perilous Sigil and Magick Cannon in the event the pawns in the party are equipped with elements that suit other situations.
Use the 'Come!' command to make sure all your pawns congregate to receive the effect.