Overview
Fubgun’s takeaway from the 0.5 reveal: Cast-on-Critical Comet Bloodmage still works the same as it did in 0.4, despite the spell-leech nerf that was supposed to kill it. The fix is a two-point swap on the ascendancy tree — drop the spell-leech nodes that powered the old sustain and pick up Sanguine Tides instead. That single change keeps the playstyle, the damage profile, and the screen-clearing potential of the previous patch intact.
Mechanically the build still revolves around stacking critical strikes on a CoC trigger to dump Comets onto packs and bosses. The Bloodmage life-cost engine is what makes it special: every spell cast bleeds life, and the new sustain layer recycles that life back into flask charges fast enough to keep playing forever. Because the loop is self-feeding, the build no longer needs leech, no longer needs Olroth’s Resolve, and no longer needs a header belt — any instant life flask plus the two ascendancy points are enough to recreate the 0.4 experience on a 0.5 character.
This is a video raising the alarm, not a polished how-to guide. The creator openly hopes the interaction is patched before 0.5 ships. Treat the entry as a working snapshot of a known-broken build — if the loop survives launch day, it will be one of the strongest setups in the meta; if Sanguine Tides is reworked, the build returns to needing a real sustain plan.
Pros & Cons
Pros
- Identical damage and playstyle to the 0.4 CoC Comet Bloodmage that dominated the league
- Sustain is gear-independent — the Sanguine Tides loop works without spell leech, Olroth’s, or a header belt
- Scales across budgets: a Standard-league character converts with two ascendancy respec points and nothing else
- Strong in both mapping and bossing footage — infinite flask sustain is the same whether you’re sweeping packs or facing a pinnacle
Cons
- Spam-one-button gameplay is brain-numbing and exists at GGG’s mercy — expect a pre-launch or day-one nerf
- Demonstrated on a mirror-tier character with Temporalis, so the showcased damage numbers are not representative of a fresh character
- No defensive plan is shown in the video — the focus is purely on the life-flask sustain trick
- Requires the patched Sanguine Tides interaction to keep working — single-line patch notes can delete the entire build
Key Skills
- Comet — primary cold spell, triggered repeatedly through Cast on Critical for AoE burst
- Cast on Critical — the engine: keeps Comet uptime tied to your crit rate while you cast a cheap trigger spell
- Life Flask spam — not a skill in the gem sense, but the literal core mechanic; pressing your flask key drives the entire sustain loop
Gear & Anointments
The headline ascendancy choice is Sanguine Tides, which grants “50% less life recovery from flask. Gain one life flask charge per 4% life spent.” Combined with Bloodmage’s life-cost casting, this generates flask charges faster than you spend them, creating the infinite-sustain loop the video showcases. The two points come from respeccing out of the spell-leech nodes that powered 0.4 sustain.
For flasks, any instant-recovery life flask works — the video specifically calls out that an instant life-recovery belt (in place of a header belt or Olroth’s Resolve) is also a valid setup. Beyond those, the build is the same CoC Comet shell that 0.4 players already know: high crit, cold-spell scaling, and end-game uniques like Temporalis for mobility on the high-budget version shown in the footage. The video does not enumerate a full gear list — players porting from 0.4 should keep their existing setup and only swap the ascendancy nodes.
Endgame Notes
Fubgun demonstrates the build on both map clears and a boss encounter, with the boss segment specifically highlighting how flask spam alone is enough to sustain through incoming damage. There is no leveling or campaign guidance in the video — the entry assumes you already have a Bloodmage and is purely a 0.5 sustain workaround. If you do not have an existing Bloodmage to convert, treat this as an endgame respec target rather than a league-starter plan.
Credits & Source
Build credited to Fubgun. See the source video for the full demonstration of the flask-spam sustain loop and live gameplay footage: CoC Comet Bloodmage Is Still The BEST Build In 0.5! - Path of Exile 2.