|“||Sacrifice some protection for a higher magic limit, and harvest magic from defeated foes!||”|
The Conjurer's Coat is a reasonably cheap armor at a cost of 4000 gold. It adds 50 points to Shovel Knight's Magic Capacity as well as ensuring enemies drop magic jars, the trade-off is that the armor doubles the amount of damage Shovel Knight takes.
These properties means its usefulness fluctuates throughout the game. On the one hand the extra magic is more useful in the early game when Shovel Knight has less magic but the extra damage penalty is also more threatening in the early game when Shovel Knight has less health. It may be wise to use the Phase Locket liberally to avoid damage as far as possible.
It's worth noting that it's far cheaper to get an extra 50 magic through this armor than through magic upgrades; it would cost 10300 gold to boost Shovel Knight's magic from 30 to 80.