Cresselia: Ban
reason: Cresselia, with its monstorous defensive stats, and decent speed, was always a force to be reckoned with in the lower tiers, Cresselia has many different sets it can run, from a wall, to Calm Mind, to weather support, to dual screens, and all are dangerous. the wall is incredibly bulky and can cripple sweepers with thunder wave, pokemon that would normally counter the Calm Mind set, i say that calm mind is actually the least broken set, as its lack of an initial offensive presence and tendency to get beaten down by things such as bulky Klinklang and SD roost scyther and CB durant, but the sheer threat of calm mind cress causes many of these pokemon to switch into the wall set and be crippled to thunder wave. by far, the lunar dance set is the most dangerous. i used a trick room + lunar dance cresselia and saw that many teams could not handle the same pokemon twice, allowing the newly healed up pokemon to rip holes in the team. the same thing can be done on weather teams, or with dual screens, this is what makes cresselia broken, dont say that mesprit can do this too, cause mesprit is MUCH easier to ko than cresselia during the process, and the slightly larger offensive presence often isnt enough. lunar dance is what makes cresselia broken, it can provide support more times, more reliably and more effectively (moonlight) than all other other screeners. and lunar dance is a great indirect holepunching move because most teams cannot deal with the same threat twice. i say ban
Porygon-z: Ban
reason: Porygon-z was always a powerful force in the metagame, from scarf to specs to agility, and i believe it is ban-worthy, simply for its specs set. when porygon-z comes in at the right time, it can easily take down a pokemon, taking out a vital part of the opponents team, there are no safe switch- ins to a download boosted specs tri attack, and behind screens, the agility LO set becomes impervious to priority and nukes the opponents entire team, nasty plot breaks through stall like no tommorow, while scarf is an amazing revenge killer. under the right hands, porygon-z is a complete monster. that can easily take down several pokemon per match and be impossible to wall. i say a ban is the correct thing to do.
Honchkrow: Do Not Ban
reason: Honchkrow, while a powerful force in the metagame, does not deserve to be banned at all, Honchkrow has plenty of checks of counters. including but not limited to Regirock, Klinklang, Steelix, Entei, Rotom, Stunfisk, Ampharos and so on, Honchkrow's low speed makes it set up bait for anything that is faster than it, and the wallbreaker set is too slow and frail to sweep. Honchkrow may be good at punching holes in a team, revenge killing, and late game sweeping, but people have learned to adapt to honchkrow. its just another threat, not to powerful.