Help with my team please

[Kris]

Now whoever told you Swords dance Scizor sucks is wrong. Swords Dance Scizor is amazing. Mega Scizor is unbelievably strong thanks to an Ability called Technician boosting the power of moves with 60 Power or less. First up, Bug Bite, for a lack of a better term, sucks. It gets boosted by Technician but it's competitive use is very lackluster. Stealing Berries is more a maingame thing tbqh. Have you heard of U-Turn? U-Turn is a move that Scizor can use to damage an opponent and switch out to a different Pokemon. For example, you can U-Turn on say, Torkoal who would use Eruption, switch into Swampert to tank the hit. U-Turn is a very useful attack and you want to replace Bug Bite for this. Aerial Ace is also not needed on Scizor as it doesn't get STAB from it and a much better option exists. Defog clears any hazards on your side of the field like Stealth Rock, Spikes and Sticky Web. Swap Aerial Ace for Defog or Swords Dance. Finally Bullet Punch and Roost can stay.Nature will want to be Adamant. EVs for this set are as follows: 64 Attack to 2HKO non-defensive Zygarde with Bullet Punch, 248 Hp and 120 Defense EVs to optimize Mega Scizor's bulk, 16 Special Defense EVs to avoid +1 Magearna's Thunderolt from being a 2HKO and 60 Speed EVs to outspeed and U-Turn on Assault Vest Magnet Pull Magnezone.

As best girl @FireTaco said, swap Psychic for Flash Cannon on Lucario and I'll add on telling you to give it Steelium Z.

Ttar looks A-Ok

Baton Pass is banned in OU, so give it Psyshock which hits Chansey better because Psyshock targets the opponent's Defense and not Special Defense, Shadow Ball over Psychic, give it a Focus Sash and a Timid Nature.

Gengar's Ability is Cursed Body. You want to put 252 EVs to Special Attack because Gengar needs to as much damage as possible. Instead od Destiny Bond, give it Will-o-Wisp. Air Balloon makes Gengar immune to Ground type moves and is kind of like a fake Levitate, so consider that.

Hope it helps