What deck does it go in? Red is pretty much THE hard aggro color. Sure you could occasionally copy a StP or Vindicate against the control deck but it could also often sit dead in your hand for lack of targets against other aggro decks and midrange Stompy.
seconded, being *free* is a huge plus for chandra, because youcan play large instants and sorceries that can lead to huge blowouts, unlike other cards with this effect she isnt a dead card if no one plays any instants or sorceries.
If you've played these cards in any format, you'll see why they won't work. The require narrow situations, you can't always leave mana up, and oftentimes when you do, your opponent still gets more value out of their spell than you do.
Redirect is better than Twincast in most situations, and Counterspell is better than either in all but the rarest of situations. Heck, Negate is better than Redirect because it can counter non-targeted spells like ramp, draw, tutors, wraths, and things that say "target opponent" or what-have-you.
Being able to Fork your opponent's spell is nice and is certainly very good in corner cases... but if my own deck didn't have a good number of worthwhile cards to Fork, I wouldn't even run it.
Very simply, why don't I see these on more lists?
I'm officially proposing we retire the word "insane" from the MtG vocabulary.
"The best way to be different is to be better" - Gene Muir
Cubes:
Modern Banlist Cube
Monocolor Budget Cube
http://cubetutor.com/cubeblog/993
http://www.cubetutor.com/cubeblog/23690
Juju Alters - Altered MTG Cards
seconded, being *free* is a huge plus for chandra, because youcan play large instants and sorceries that can lead to huge blowouts, unlike other cards with this effect she isnt a dead card if no one plays any instants or sorceries.
http://forums.mtgsalvation.com/showthread.php?t=484979
Redirect is better than Twincast in most situations, and Counterspell is better than either in all but the rarest of situations. Heck, Negate is better than Redirect because it can counter non-targeted spells like ramp, draw, tutors, wraths, and things that say "target opponent" or what-have-you.
I mean, you'll feel pretty foolish when you choose Redirect over something like Negate and your opponent taps out for Cultivate and Green Sun's Zenith or something. Or Recurring Nightmare. Or Survival of the Fittest. Or Sword of X and Y. Or Sulfuric Vortex. "You're so lucky! I guess I'm going to die because I left Redirect or Twincast up, and my opponent didn't draw enough Lightning Bolts." "Fork you and your Armageddon!"