"Cannot Be Used as Material" Is a Condition, Not a Monster Effect

Performapal Odd-Eyes Metal Claw — "...this card cannot be used as a Fusion Material Monster."

Text like "cannot be used as a Fusion / Synchro / Xyz / Link Material" (or "as material for the Summon of...") is a condition — a property of the card — not a Monster Effect. Under PSCT, not every sentence without a colon/semicolon is a Continuous Effect; restriction conditions are part of the card.

Contrast A Monster's Effects Apply Only in the Monster Zone: that rule turns a card's Monster Effects off when it leaves the field; a material restriction is not a Monster Effect, so it does not turn off that way. Like the Highlander "only control 1" clause, it is a non-negatable rule baked into the card.

Effect negation does NOT lift it

The clause is a condition, not an effect, so negating the monster's effects does not remove it:

• Skill Drain, Effect Veiler, Forbidden Chalice, Infinite Impermanence, "its effects are negated" — none let you use the monster as material. The restriction stays in force.
• It applies even when the card is not a face-up monster. Official OCG ruling (2016-09-08, Fullmetalfoes Alkahest equipping Performapal Odd-Eyes Metal Claw): Metal Claw's "cannot be used as Fusion Material" text is not a monster effect, so it still applies while the card is equipped in the Spell & Trap Zone. Treat face-down and other off-field states the same — the restriction rides with the card.

Exception: restriction APPLIED by another card

Distinguish a printed condition (above) from a restriction applied by a separate card's effect (e.g. making opponent's monsters unusable). An applied restriction is an effect — if that source's effect is negated or leaves, it lifts. Check where the restriction comes from.

"...the turn it is Summoned" variant

Some cards restrict material use only during the turn of the summon:

"...cannot be used as material for a [Summon], the turn it is [Special] Summoned."

Same nature — a condition, not negatable — but the window is limited: blocked only on that summon turn; on a later turn the monster is usable. Tied to that summon, so re-summoning later starts a fresh check.

Read which Summon type and scope

• "Cannot be used as a Fusion Material" blocks only Fusion; the monster may still be Synchro/Xyz/Link/Tribute fodder. Match the named type(s).
• "Cannot be used as material" with no type named blocks all material uses.
• "...except for the [Archetype] Summon of a [X] monster" — the exception is part of the condition; it permits exactly that use and nothing else.

Super Polymerization / fusion-tool relevance

A monster with a "cannot be used as a Fusion Material" condition cannot be Super Poly fodder or a steal target. Super Polymerization's result being "unaffected by other cards' effects" does not help: the restriction is on the material, and is a condition, not an effect. Exclude such monsters from Fusion target generation and Super Poly steal lines.

Judge calls

• "Skill Drain is on, can I use it as Fusion Material now?" → No. Not a monster effect.
• "It's face-down / equipped — does the restriction still apply?" → Yes, the clause rides with the card.
• "It says the turn it was Summoned — next turn?" → Yes next turn; blocked only on the summon turn.
• "Can Super Poly steal it?" → No, if it can't be Fusion Material.
• Restriction applied by another card → lifts if that card's effect is negated/removed.

Sources

• YGOrganization OCG 2016-09-08 (Fullmetalfoes Alkahest / Performapal Odd-Eyes Metal Claw): "cannot be used as Fusion Material is not a monster effect"
• YGOrg "Demystifying Rulings Part 1: PSCT". Cross-refs: 35, 41, 09, 04.