Gengar: 8/10
I'm decucting for the picture, and the Retreat Cost for Gengar being too high. A typical Gengar's retreat cost is usually a maximum of 2 colourless energy. The attack is a little bit too complicated, and would be a bit of a bother to people with weak math skills.
Haunter: 6/10
The most major flaw is that the picture inside the circle on the left os the Stage One sign is a picture of HAUNTER, when it should be a picture of it's pre-evolution, GASTLY. The energy symbol under Resistance is a bit blurry. The retreat cost is too high, most Haunters have a retreat cost of 0 to 1 colourless energies.
Gastly: 9/10
Energy symbol for Resistance is too blurry. I love the attack =)