This tagline is normally used by ‘epic’ or elder creatures. This add-on effect changes the effect of a regular tagline (such as adding “Terror” to “Paralysis” to get “Terror Paralysis”) to an effect that cannot be resisted and will affect the target regardless of any protections. It can also affect creatures that are normally immune to such effect.
For example: “Terror Paralysis” or “Paralyzing Terror” will cause the target to suffer the effects of paralysis regardless of whether they could resist the effect, if they were immune to the effect, or had some type of protections against the effect. This would go the same for any effect the “Terror” tagline would accompany, including Death effects.