4 Oct 2019
The Circle of Loyalty's triggered ability resolves before the spell that caused it to trigger. It resolves even if that spell is countered.
4 Oct 2019
The Circle of Loyalty's triggered ability won't trigger when you cast it because it's not on the battlefield yet.
4 Oct 2019
Once you announce that you're casting a spell, no player may take actions until the spell has been paid for. Notably, opponents can't try to change by how much a relic's cost is reduced.
4 Oct 2019
To determine the total cost of a spell, start with the mana cost or alternative cost you're paying, add any cost increases, then apply any cost reductions. The mana value of the spell remains unchanged, no matter what the total cost to cast it was.
4 Oct 2019
The cost reduction ability reduces only the generic mana in the relic's cost. The colored mana must still be paid.