The Conviction aura provided by Infinity maximizes the effects of the high-level Chain Lightning that the weapon produces. For nearly every character that deals elemental damage, this is the best mercenary weapon since it actively reduces resistances, vastly increasing the damage output of the character. Only the rare builds that deal magic damage, poison damage or physical damage do not receive significant benefit from the Conviction aura on this weapon.
Note that the decrease in enemies' Lightning Resistance only works for the character equipped with it, so Lightning-based Sorceresses with an Infinity-wielding Mercenary will only benefit from the Conviction aura. Sorceresses who use lightning spells may even want to wield Infinity themselves to make use of the massive enemy lightning resistance reduction, or opt for Crescent Moon instead.
Infinity is a prized polearm because it requires two Ber runes and can only be constructed by Ladder characters.
50% Chance To Cast Level 20 Chain Lightning When You Kill An Enemy
Level 12 Conviction Aura When Equipped
+35% Faster Run/Walk
+255-325% Enhanced Damage
-(45-55)% To Enemy Lightning Resist
40% Chance of Crushing Blow
Prevent Monster Heal
0.5-49.5 To Vitality (Based on Character Level)
30% Better Chance of Getting Magic Items
Level 21 Cyclone Armor (30 Charges)