This happens every time a new set comes out. Cards that have previously been ignored or phased out start popping up again thanks to new possible combos or counters to other playable cards. Case in point, PlasmaKlang from Plasma storm made Klingklang BW and Cobalion playable. As a result of that, Benchtini saw play as a counter.
Speaking of Cobalion, that's one of the cards that I think will resurface again. For two energy, Energy Press KOs a fully powered Xerneas EX. Iron Breaker with Muscle Band takes out any other metal weak pokemon.
There's also Scizor (BC) that has a reasonably prices attack that does 100. This is probably a stretch, but it is a possibility.
Hurricane Kick Lucario from PS is another one that I think could start to pop up. With a rainbow or blend energy, it can hit two types for weakness. Plus, it's attack is pretty good on it's own (can easily take out EX's late game). I'm actually surprised it hasn't seen more play prior, but that's for a different topic.
EXP Share: Another one I think is underrated. If you're playing pure fairy Aromatisse, you could have this for insurance against OHKO decks. You could theoretically save a lot of energy with just one of these (until they play tool scrapper).
Dialga EX: As a counter to BKEX and Rayquaza EX, two pokemon that OHKO everything. Again, fairy decks that run only fairy energy could take advantage of this as there aren't many other Dragon Counters without wierd energy requirements. At worst, it's just another big tanky pokemon that's excellent for fairy decks.
Salamence (DRV): The one with the hand disruption ability. It's similar to red card and if that becomes popular, I could see people playing this. Use this or red card followed by a Ghetsis an Mental Thrash with malamar could deplete an opponents hand to zero. If this becomes popular enough, Salamence PLB could be an easy tech against decks using a lot of tools.
Fliptini: Speaking of malamar, I hear it's been ruled that you can reflip for malamars attack.
Celebi EX: Possible combo with Trevenant / Phantump with astonish. Hand disruption under item sounds nasty.
Jolteon (DEX): Can do 60 for one. If Eeveelution decks remain popular, I could see this being put in to deal with Yveltal and Lugia (silver bangle) or Empoleon (muscle band).
Espeon (DEX): Especially if Gorgeist becomes popular. Not to mention the numerous effects this negates that Virizion doesn't.
There are probably some I'm missing, but those are the big ones.
Speaking of Cobalion, that's one of the cards that I think will resurface again. For two energy, Energy Press KOs a fully powered Xerneas EX. Iron Breaker with Muscle Band takes out any other metal weak pokemon.
There's also Scizor (BC) that has a reasonably prices attack that does 100. This is probably a stretch, but it is a possibility.
Hurricane Kick Lucario from PS is another one that I think could start to pop up. With a rainbow or blend energy, it can hit two types for weakness. Plus, it's attack is pretty good on it's own (can easily take out EX's late game). I'm actually surprised it hasn't seen more play prior, but that's for a different topic.
EXP Share: Another one I think is underrated. If you're playing pure fairy Aromatisse, you could have this for insurance against OHKO decks. You could theoretically save a lot of energy with just one of these (until they play tool scrapper).
Dialga EX: As a counter to BKEX and Rayquaza EX, two pokemon that OHKO everything. Again, fairy decks that run only fairy energy could take advantage of this as there aren't many other Dragon Counters without wierd energy requirements. At worst, it's just another big tanky pokemon that's excellent for fairy decks.
Salamence (DRV): The one with the hand disruption ability. It's similar to red card and if that becomes popular, I could see people playing this. Use this or red card followed by a Ghetsis an Mental Thrash with malamar could deplete an opponents hand to zero. If this becomes popular enough, Salamence PLB could be an easy tech against decks using a lot of tools.
Fliptini: Speaking of malamar, I hear it's been ruled that you can reflip for malamars attack.
Celebi EX: Possible combo with Trevenant / Phantump with astonish. Hand disruption under item sounds nasty.
Jolteon (DEX): Can do 60 for one. If Eeveelution decks remain popular, I could see this being put in to deal with Yveltal and Lugia (silver bangle) or Empoleon (muscle band).
Espeon (DEX): Especially if Gorgeist becomes popular. Not to mention the numerous effects this negates that Virizion doesn't.
There are probably some I'm missing, but those are the big ones.