Mage support
Burst support mages-

Other than Zyra, the other 3 are somewhat played in mid-lane but still have a better play-rate and win-rate as supports. However, even at support position they are at the bottom of the list : check below
http://na.op.gg/champion/statistics
If they are not viable picks as supports, then they should be reverted back to mid. I can see how this can be difficult for Zyra, but i know for a fact that if you increase Brand's and Lux's early game farming, they would be played a lot more in mid lane. Lux just needs an increase in her E radius, whilst brand needs more AP ratio on his E so W and E can kill caster minions early on.
and that magic shield exist when the mages are the ones that get crushed in mid lane.