Crown of Reflection

Instant - Destroy this: Destroy target Illusionist aura you control. If you do, you may put an Illusionist aura with cost less than or equal to the aura destroyed this way from your hand into the arena. Activate this only during your action phase.

Arcane Barrier 1

Rulings

From the Everfest release notes

You can only prevent one arcane damage per Arcane Barrier 1 per damage event.
Players cannot respond to the prevention as it is a replacement effect.
To fully prevent a card dealing 3 arcane damage, you would require three Arcane Barrier 1 and three resources to prevent it. To fully prevent 3 Runechant tokens (3 instances of 1 damage from different sources). You would require one Arcane Barrier 1 and three resources to prevent it.
If a token Aura is destroyed by Crown of Reflection, you may put an Illusionist aura from your hand into the arena with a cost of 0. In this way tokens are assumed to have a cost of 0 because the effect assumes and requires the cost to be defined, instead being conditional on it.
If the aura destroyed has a triggered effect that triggers on its own destruction (e.g. Haze Bending), that effect will trigger. If the illusionist aura you put into the arena has a triggered effect that triggers on other aura’s destruction, that effect will not trigger because it was not in the arena at the time the previous aura was destroyed.
If the Aura is destroyed before the activated layer resolves as a layer on the stack, the layer fails to resolve and you do not gain the benefit of putting an aura into the arena.

Keyword notes

Arcane Barrier - is one of the most common ways to prevent arcane damage. If you would be dealt arcane damage you may pay X{r} instead to prevent X arcane damage that source will deal.

You can have multiple instances of arcane barrier.
You can only prevent one arcane damage per arcane barrier per source.
You can prevent arcane damage you do to yourself.
Players cannot respond to the prevention.
To fully prevent a card dealing 3 arcane damage, you would require 3 arcane barrier and 3 resources to prevent it. To fully prevent 3 Runechant tokens (3 instances of 1 damage). You would require 1 arcane barrier and 3 resources to prevent it.
Preventing arcane damage does not destroy the equipment with arcane barrier (unless otherwise specified).
Arcane barrier is a replacement effect. It does not use the chain. Players cannot respond to the prevention.
Each source of arcane barrier can replace damage 1 time per source. To fully prevent a card dealing 3 arcane damage, you would require arcane barrier 3 and 3 resources to prevent it. To fully prevent 3 Runechant tokens (3 instances of 1 damage). You would require arcane barrier 1 and 3 resources to prevent it.
If a card has Arcane Barrier 2, you must pay the full two resources even if it only prevents one damage. You cannot choose to pay one resource to prevent one damage.
You can have multiple instances of arcane barrier, for example Nullrune Hood, Nullrune Cloak, and Nullrune Gloves.
Arcane barrier can be used every time you would be dealt arcane damage. It’s not limited to once per turn.
Each instance of arcane barrier you control can be used 1 time only, each time a source would deal arcane damage to you. For example if a source would deal 5 arcane damage to you, and you control two cards with arcane barrier 1, you will in total be able to prevent 2 arcane damage this source would deal to you.
To fully prevent a card dealing 3 arcane damage, you would require 3 arcane barrier and 3 resources to prevent it. To fully prevent the arcane damage from 3 Runechant tokens (3 instances of 1 damage), you would require 1 arcane barrier and 3 resources to prevent it.
A equipment with arcane barrier does not move to the chain when arcane barrier is used.
You can prevent arcane damage you would deal to yourself.
Players cannot respond to the prevention. Arcane barrier is a replacement effect, not an activated or triggered ability.
To fully prevent a card dealing 3 arcane damage, you would require 3 arcane barrier and 3 resources to prevent it. To fully prevent 3 runechant tokens (3 instances of 1 damage from difference sources). You would require 1 arcane barrier and 3 resources to prevent it.