That would be because the damage is the red aspect of the Izzet card.
In order for a card to be multicolour, the card's effects have to make sense in both colours. This is why
Electrickery is monored and not Izzet.
What you have here doesn't have any effect that makes sense in blue.
Not
exactly.
fantana, there are two kinds of multi-colored cards in Magic. You have
hybrid cards like
Vexing Shusher, which can be cast as a purely red card, a purely green card, or anything in-between. Those cards have to have effects that are OK for
both of those colors - you couldn't have a card that costed
that dealt damage to a creature, for example, because you could cast that spell for
and Blue doesn't get to deal damage.
Gold cards, on the other hand, are cards like your Lightning Vortex, which cost mana of two or more colors. Those cards
need to justify being multiple colors, so they generally have effects drawing from two different colors. Take
Blast of Genius, for example - the card draw is blue and the damage is red. Sometimes there will be effects that
only show up in combinations of colors - cards that care about the number of instants and sorceries in your graveyard
and exile only show up on cards that are
both red and blue, which is why Beacon Bolt is multicolored.
Lightning Vortex is
crazily overcosted the way you currently have it - compare it to
Fight with Fire. It has the same base effect (deal 5 damage to a creature) for roughly
half the cost (
and
are roughly the same in terms of how difficult they are to cast), has an arguably better kicker (the kinds of decks that would run something like this are
probably going to want the option to deal 10 damage to their opponent's face or wipe out a planeswalker instead of a really hard to cast sweeper), and is uncommon instead of rare.
Lightning Vortex is also a
very Red card. Why do you want it to be Blue
and Red? That just makes it harder to cast for no good reason.
My personal two cents is that trying to convert cards from one game to another is
not a good idea, unless you understand
both games really well. Due to the core rules of both games, effects that are really strong in one game can be really weak in the other one.
For example, Graceful Charity is effectively
banned in Yugioh because it's
really strong. In Magic, "draw three cards then discard two cards" at Sorcery speed would
probably cost
, at common. This is because Yugioh doesn't have a limit on the number of Spells or Traps you can play each turn, while Magic
effectively does (because cards cost mana to play), so card draw is a safer effect.
If you're just starting off with Magic design,
stick to the color pie. Going into designing Magic cards thinking "I'll just ignore the color pie if I want to" is like learning to write in a new language and going "I'll just ignore grammar when I want to" - it's a recipe for doing a crappy job.