Summoning Potion

An extra minion slot is the obvious buff for a summoner, but it is arguably better value for everyone else. Any class can equip a cheap staff, throw out a permanent minion and get free damage ticking away while they aim their real weapon. This potion turns that one free slot into two.

It also stacks with the Bewitching Table, so buffing at the table and drinking on your way out the door gives you both at once. Drink before you place your minions, never after, because you can only summon up to your current cap and the extra slot goes to waste if you fill up first. Summoners should treat it as mandatory for every boss; the ingredients are common enough that rationing it makes no sense.