Xander was fully aware of the gravity of the situation and the danger that Tang Yue was in.
Illusionary spells were mysterious spells that used mental energy as the basis for their magic.
The easiest and surest way to block them was to physically coat yourself with a mana barrier inside and out.
But not just any barrier worked.
The barrier had to be thick and strong and capable enough to withstand the power behind the illusionary spell.
Erecting such a mana barrier was a time-consuming and energy drain process.
No one at least under the Saint realm can possibly have this kind of a mana barrier switched on 24/7.
But that's what exactly an illusionary spell defense needed.
These long-range spells could be cast silently at any point in time.
It was almost impossible to guard against them every single day and at all times.