Build:Hierophant

Full Build Details
'''NOTE: This is an endgame build, the ultimate form of lightning mage/priest. Multiple playthroughs and the use of Legacy Chests are needed to obtain some of the equipment.'''

The idea of this build is to maximize the effectiveness of lightning magic. The equipment is chosen in a way to maximize lightning damage bonus and mana cost reduction. As a result, most, if not all, of the chosen equipment has mediocre protection and damage resistances, while this should not be a serious problem as players with this build should stay at range.

With this build, it is possible to achieve 70% lightning damage bonus and -75% mana cost.

Passives
Apart from the mentioned skills, you should also (try your best to) obtain these passive skills during your playthrough.

Spiritual Communion
This passive skill is obtained by. It gives 10% lightning damage bonus (as well as other elemental damage bonuses which are not important for this build).

Runic Prefix
One of the skills in the Rune Sage skill tree. This skill and Internalized Lexicon are mutually exclusive (i.e. you can only choose one of the two). Runic Prefix strengthen your Runic Magic by adding extra effects to them, while Internalized Lexicon eliminates the requirement of equipping Lexicon in your off-hand to cast runic spells. Choose Runic Prefix for this build.

Items
Apart from the mentioned equipment, you should also obtain these items.

Mage Tent
One of the best, if not the best tent for mages. It gives a buff of -15% mana cost to players after they slept in it. The buff lasts for a whopping 50 minutes long. It also reduces the Mana Burn rate from sleeping by 50%.

Alternative Breakthroughs
The Leyline Connection is a nice-to-have breakthrough for every mage build, because (1) passive mana regen allows mages to have better sustainability so that you do not have to rely on consumables too much and (2) Philosopher itself is a great magic skill tree. You can swap skills and equipment at any time to adopt an entirely different mage build. For example, the Archmage (stacking Sigils) and the Cryomancer (Frost mage). While Well of Mana and Shamanic Resonance are must-haves, Leyline Connection is NOT. You may consider other alternatives depends on your play style.

Spellblade's Awakening
The breakthrough of Kazite Spellblade. It increases your maximum health, stamina and mana by 15. More mana is always a good thing for mages.

Swift Foot
The breakthrough of Mercenary. It increases your movement speed by 10%. A nice skill for this build as you will be using hit-and-run tactics a lot.

Alternative Weapons
The Radiant Wolf Sword mentioned is great to use as a backup weapon, because (1) it only deals lightning damage, so that it can take the full benefit from the 70% lightning damage bonus and (2) it has infinite durability. While you may also consider other alternatives depends on your play style.

Gold-Lich Mace
This mace has on hit 60% chance to apply Doomed to your target, which lowers its lightning resistance and damage. It increases the damage of your spells, while it has lower overall damage than Radiant Wolf Sword.

Gold-Lich Sword
Same reason as Gold-Lich Mace. While Gold-Lich Mace is generally better because it hits harder, but the choice is yours.

Runic Blade
This weapon is a magic sword summoned using Runic Magic. You cannot buy or craft it. If you have learnt Runic Prefix (which you should), this blade would gain Divine Light Imbue by default and deal slightly more damage than the Radiant Wolf Sword. The only downside is, as a spell it only lasts for 3 minutes, so you have to resummon it from time to time.

Combos
''Runic Protection, Runic Lantern and Blessed. You should make sure these buffs are always active.''

''Runic Lightning. Requires Runic Lantern to be active. This is your primary attack, spam it.''

''Place the Runic Trap on the Sigil of Wind. Then lure your target (victim) to walk on it. Once your target is within the area of the Sigil of Wind, Runic Trap will be detonated automatically. Cast Conjure to produce a Lightning Strike for extra damage. you do NOT have to stand inside the Sigil for the effect to occur.''

''Reveal Soul will reveal the Soul Spots (blue orbs) on fallen human enemies and corpses. And casting Conjure near these blue orbs will summon a ghost to aid you in battle. The ghost is not very strong but it will pull some aggro to give you a safer spot position to cast spells.''

Similar to the previous combo, but instead of summoning a ghost, it will restore 50% of your maximum mana.

''Casting Runic Heal will consume Runic Protection. So remember to re-cast it.''