Sephiria Boss Preparation: The Pre-Boss-Room Checklist

Sephiria does not publish boss attack patterns and neither does this site — our chapters and bosses page lists who you fight and where, not how they swing. What is documented, across every clear we have read, is what a run should have before the boss door: which floors the run is actually lost on, what to buy at the fixed shop, when to hire Colin, how much MP to leave in the tank, and which Hard Mode rules quietly change the fight. This page is that checklist.

Where boss fights are really lost

The most useful sentence in the only published Hard Mode tier 50 clear is about floors, not bosses: "the hardest part of the higher tiers is the first 3 floors." The build is incomplete, tank items are not in yet, and the author's failed attempts "mostly come from not prioritizing tank early enough and dying to Floor 1–3 bosses." The advice that follows is one line — "Don't skimp on tank!!" — and it is the first item on the checklist for a reason: the boss you lose to is usually the one you reached under-built, not the one with the hardest moveset.

The fire Blade guide adds the other half of that lesson from the damage side. On the Hard Mode 60 final boss its build does "about a tenth" of its training-dummy DPS. A number that looks like a clear on the dummy is not a clear; plan for the boss you can survive, not the one you can burst.

The checklist, floor by floor

Before you leave the start node. Every floor after the first opens on a fixed store with a training doll next to it (Early Access structure, unchanged in 1.0 as far as any note says). That is the moment to sell filler, buy the potion you are missing, and hit the doll once to see whether your damage is where you think it is — see the run events page for what else the start node can hold.

Bag check. Ask the talents page's question — Endure 5's Foundation tablet is a free row of +1 from the start of the run — and the inventory grid's: is a max-3 artifact sitting on a +5 cell? Fix that with the Q / E preview before a boss, not after.

500 Leaf in reserve. Colin (spelled Collin in the 1.0.24 notes) sells a #Companion token for a flat 500 Leaf, does not bargain and does not buy. Two guides independently keep 500 in hand for him: the Companion build because he "has lots of HP and pulls aggro on the front line," and the Early Access basics guide because "if the final boss feels too difficult, recruit Colin — she is a great punching bag." Since 1.0.24 his dialogue is disabled once he joins.

MP for the escape. The Companion guide's standing rule is to keep enough MP for the Smokescreen spellbook, because it is your dodge when a dash is not available and "one hit can be fatal." The same logic applies to any build whose special or block runs on MP: walk in with the pool full, not with the last cast spent on the doll.

Potions. Drink stat potions freely — the Companion guide's phrasing is "drink them all, it comes out positive" — and remember that since 1.0.24 dropped potions land separately rather than stacked, so a floor's worth is visible on the ground.

The Blood Donation trade. The Iron Maiden takes 33% of your current HP for an artifact. Killing the vampire bat in that room costs Barter and locks the Maiden, so use the Maiden first if you want both (Early Access documentation).

Rules that change the fight in Hard Mode

Two Hard Mode elements were silently broken in some boss rooms until 1.0.26: Tension was not being applied at all in certain fights, and Festival of Blood was triggering on targets already defeated. If a tier felt inconsistent between bosses in early August, the modifiers were, and the Hard Mode page has the full element list.

In multiplayer, the 1.0.21 hotfix scaled Blood Festival healing by party size — 66% at 2 players, 50% at 3, 33% at 4 — because four players taking hits was healing bosses faster than the group could damage them. And since 1.0.26, temporary HP from a teammate's revive survives healing but is wiped whenever your maximum HP changes: do not walk into a boss room straight after a Green Heart if you are living on revive HP. The co-op page covers the rest.

What has changed about the bosses themselves since launch

Nothing we can find is a retune of a mid-game boss after 1.0.19. The record is fixes:

The final boss and endings page has the phase-by-phase context for the last three rows.

What this page will not do

It will not tell you the timing of a slam or the safe corner of an arena. That is a deliberate editorial position — attack patterns change between patches without always being listed, and a wrong timing is worse than none. Preparation, by contrast, is stable: the shop, the doll, the reserve Leaf, the MP floor and the tank-first order have been the same advice from an Early Access basics guide to an August 2026 tier 50 clear.