Craft guide
Runebinder +2 Ballista Chase Crossbow
Base: Siege Crossbow with fractured plus 5 to level of projectile skills (~15 div bought fractured, or fracture it yourself)
Based on Endgame Crossbow Crafting Guide
Get the fractured plus five projectile base
Buy it fractured, or buy the mod unfractured and gamble Fracturing Orbs - one in several to hit the projectile skills mod
Annul down to the fractured mod
4× Orb of Annulment—Annulment cannot touch the fractured mod - keep going until only it remains
Chaos-spam for high-tier physical damage
1× Chaos Orb—✓ tier 1-3 flat or increased physical damage
✗ miss
Divine the rolls
1× Divine Orb—This is an expensive craft - get the physical roll near max before locking the rest in
Desecrate a prefix
1× Omen of Sinistral Necromancy—
1× Preserved Jawbone—No Sovereign omen this time - the totems come from the alloy, the desecration slot is for more damage
Fill the remaining mods
3× Greater Exalted Orb—Every open mod must be filled so the alloy has only suffixes to eat
Apply The Runebinder's Alloy
1× The Runebinder's Alloy—Guaranteed plus two maximum ballista totems - it removes a suffix, never your physical prefixes
Reveal the desecration, hunting the missing damage mod
1× Omen of Abyssal Echoes—If you chaos-spammed flat physical you want high-tier increased physical here, and vice versa - plain, not hybrid
✓ high-tier physical damage
✗ miss
Strip the desecrated mod and go again
1× Omen of Light—1× Orb of Annulment—
1× Ancient Jawbone—Ancient Jawbone gives better odds on high tiers than Preserved - this loop is the expensive part, budget several attempts
Quality, runes and infusion
20× Blacksmith's Whetstone—
2× Greater Iron Rune—
1× Masterwork Rune—
1× Vaal Blacksmith's Infuser—✓ two extra ballistas, plus five projectile skills
Materials
4× Orb of Annulment—1× Chaos Orb per attempt—1× Divine Orb—1× Omen of Sinistral Necromancy—1× Preserved Jawbone—3× Greater Exalted Orb—1× The Runebinder's Alloy—1× Omen of Abyssal Echoes per attempt—1× Omen of Light per attempt—1× Orb of Annulment per attempt—1× Ancient Jawbone per attempt—20× Blacksmith's Whetstone—2× Greater Iron Rune—1× Masterwork Rune—1× Vaal Blacksmith's Infuser—Cost per pass≈0.0 ex
Expected cost≈0.0 ex
Total excludes 15 unpriced materials.