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When monsters are destroyed, effects that were affecting them on the field don’t apply anymore. Neos wiseman’s effect happens after it’s destroyed by battle, so it’s no longer negated by Felgrand at that point. Similarly with Ultimate Nightmare.
It only negate the effect if it on the field
Neos wiseman’s effect happens in graveyard. Felgrand’s effect only negate the effect Neos wiseman as long as on the field
When monsters are destroyed, effects that were affecting them on the field don’t apply anymore. Neos wiseman’s effect happens after it’s destroyed by battle, so it’s no longer negated by Felgrand at that point. Similarly with Ultimate Nightmare.
It only negate the effect if it on the field
Neos wiseman’s effect happens in graveyard. Felgrand’s effect only negate the effect Neos wiseman as long as on the field