This is a type of design we've seen a number of
times now, and at worst, it has an element of
the randomness that Lash Out or Searing Blaze
could have. You're not always going to be in
control of whether you have a dragon in play or
in your hand or not, but then again, many
different kinds of red decks want to use dragons
anyway, and it's a fairly solid card even if you
don't have one.
Today's card of the day is Draconic Roar which
is a two mana Red instant that deals three
damage to target creature and if you reveal a
dragon card from your hand as you cast it then
it also deals three damage to that creature's
controller. This is similar to Burn the
Impure or Lash Out and is a mediocre spell for
most Red decks, though even a small number of
dragons in deck assist noticeably and it could
see play in dragon themed or supported builds.
For Limited where dragons are somewhat numerous
and any removal is valuable this is an excellent
uncommon card and well worth playing even if the
second condition isn't triggered. In
Sealed this should always be included in a Red
build, potentially even as a splash. For Booster
this can be drafted as early as the second pick
and multiples work well to control the
battlefield when supported with any form of
aggressive creatures, though dragons naturally
increase the value.
Two mana for three damage is a pretty standard
fare. Thankfully, it’s at instant speed, which
makes it useful. The only problem is that it
only hits creatures. If you’re playing against a
creature-light or even creature-less deck, this
becomes a dead card.
If you have a dragon to reveal, this becomes a
much more powerful card. Two mana for a total of
six damage is very powerful. If you’re playing a
dragon-heavy deck, I would say it is worth
playing this, even with the risk of occasionally
not having a target. If you’re not playing
dragons, there are probably other better removal
spells you could play.
In limited, spells that can help kill creatures
are pretty much golden. The game often becomes a
contest of who has the most creatures on the
battlefield, so if you can win that battle, you
will win a lot more games than you lose.