Vershab breaks his long silence with few words, saying, "Nethys. It is protected with magic. One moment, please..." He then spends several long moments attempting to analyze the abjuration effects on the portal before reporting his findings to the party.

Spoiler: Mechanics
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Knowledge (Arcana) (1d20+15)[17] vs DC (15 + spell level, or 15 + 1/2 caster level for a nonspell effect)
Additional checks, if necessary: (1d20+15)[35], (1d20+15)[22], (1d20+15)[21]

If the spells are harmful and can reasonably be Dispelled, Vershab will announce as much and offer to remove them.