Archmage of Runes's first ability can't reduce the amount of colored mana you pay for a spell. It reduces only the generic mana component of that spell.
08-11-2024
wotc
Archmage of Runes's last ability resolves before the spell that caused it to trigger. It resolves even if that spell is countered or otherwise leaves the stack without resolving.
08-11-2024
wotc
Archmage of Runes's first ability doesn't change the mana cost or mana value of any spell. It changes only the total cost you pay to cast instant and sorcery spells.
Random a card of Magic: The Gathering (MTG), but you can also roll the D20 dice, random a Planeswalker, have fun with the random rules and more.