Soul Read

Soul Read is an enemy aura in Xenoblade Chronicles unique to and typical of most. It provides +200% evasion, making it almost impossible to hit the foe with physical attacks. It also allows the user to defy visions by changing to a different art as the vision completes, if the current vision was changed in some way.

Removing Soul Read is very important in defeating Telethia; only if the whole party is ether-based and does not require auto-attacks to land can it be allowed to continue. Monado Purge and Mind Blast are the provided means to do so, though Thunder is also capable, and if a can be applied somehow a successful  will also end it. That said, non-boss Telethia cannot keep the aura active for long periods.