Build verdict: v0.109 Eidolon is only as good as the Ethereal cards waiting in the Exhaust pile. Draft the replay package first, then take the payoff. An early Eidolon without setup is a promise, not a solution.
The rework changes the entire job
Eidolon now plays all Ethereal cards in the Exhaust pile and then Exhausts. Before v0.109, it exhausted the hand and rewarded a nine-card Exhaust with Intangible. The old card asked for hand size. The new card asks for pile quality.
| Old Eidolon question | New Eidolon question |
|---|---|
| Can I build a large enough hand? | Which Ethereal cards are already Exhausted? |
| Do I need Intangible this turn? | What do the replays accomplish this turn? |
| Can I afford to lose my hand? | Is the replay package worth Eidolon's cost and draw? |
That distinction removes a common shortcut. Eidolon is no longer a defensive panic button merely because its name and rarity stayed the same.
Build the pile before the payoff
An Ethereal card normally creates urgency: play it now or lose it at end of turn. Reworked Eidolon turns that loss into future inventory. The best targets are effects that remain useful when replayed later and do not depend on a narrow board state.
Prioritize a mix of jobs:
- damage that scales into elite and boss HP;
- block or mitigation that remains relevant on the Eidolon turn;
- setup that improves several following turns;
- card generation or Energy that helps finish the replay turn;
- Osty support when the replayed sequence advances a summon plan.
Avoid filling the deck with weak Ethereal cards solely to raise the count. Eidolon plays all of them, but quantity does not repair poor card quality.
Timing the first Eidolon
The first pass through the deck is setup. Track which Ethereal cards have already Exhausted and whether their effects answer the current fight. Playing Eidolon after one minor Ethereal effect is usually worse than drawing a normal card that immediately blocks or attacks.
A useful threshold is not a fixed number of cards. It is a solved problem:
| Combat problem | Eidolon is ready when the pile can... |
|---|---|
| Hallway tempo | End the fight or prevent another enemy cycle |
| Elite burst | Cross a damage breakpoint while preserving enough defense |
| Boss scaling | Reapply setup that materially improves later turns |
| Emergency defense | Produce enough mitigation without relying on the old Intangible text |
Because Eidolon Exhausts after use, the timing decision matters. Treat it like a one-shot conversion of previous Ethereal turns into one concentrated turn.
Cards and mechanics to watch
Veilpiercer rewards Ethereal sequencing by making the next Ethereal card free. Wisp supplies Energy and Exhausts. These examples show the two resources the deck must balance: useful effects entering the pile and enough tempo to survive while preparing it.
Time's Up and Doom packages can provide a separate finishing condition. Do not force every Necrobinder mechanic into the same deck. If Doom already ends bosses reliably, Eidolon should solve consistency or defense rather than compete as another slow payoff.
The Necrobinder guide explains Osty and Doom fundamentals. Read it before treating Ethereal replay as the class's only plan.
Common build failures
Taking the payoff before the package
A Rare card creates pressure to justify the pick. Resist it. If the current deck has no meaningful Ethereal cards, Eidolon may remain weak for an entire act.
Remembering the old Intangible effect
The beta rework does not grant Intangible through the previous nine-card condition. Count actual block, enemy intent, and replayed defensive effects before committing the turn.
Replaying effects with no current target
An Ethereal debuff can be excellent in one matchup and wasted in another. Eidolon plays the pile as it exists; it does not let every effect wait for its ideal enemy.
Ignoring draw order
Eidolon drawn before the pile is stocked can be dead weight. Draw and deck size still determine whether the payoff arrives after setup. The small deck vs large deck guide is useful here.
Draft checklist
Take Eidolon when:
- at least two meaningful Ethereal cards already contribute to the deck;
- the deck can survive the setup cycle;
- the replay turn solves damage, defense, or scaling rather than creating spectacle;
- draw and deck order make a second-half payoff realistic;
- the next boss rewards concentrated value.
Pass when the deck only has incidental Ethereal cards, needs immediate front-loaded damage, or already owns a cleaner finisher.
Source and branch note
The rework is beta-only as of July 20, 2026. Its text was verified against Mega Crit's official v0.109.0 notes and the Untapped change summary. The linked card page displays the current stable version until promotion.
FAQ
Does Eidolon replay every Exhausted card?
No. The new text specifies Ethereal cards in the Exhaust pile.
Does it still grant Intangible?
Not through the old nine-card condition. Build the turn around the actual replayed effects.
Is more Ethereal always better?
No. Each Ethereal card should still do a useful job before Eidolon is considered. A larger weak pile produces a larger weak turn.
