Garchomp
I decided to use Garchomp as a stealth rocks lead. I noticed that it's been fainting quite easily after setting stealth rocks. I'm thinking of replacing swords dance with hidden power ice to counter other leads like Landorus-T and other Garchomps. I've also been wondering if I should just replace Garchomp with Landorus-T. It has a higher attack stat which can help get a few KOs early on. If I replace with Landorus-T I would run stealth rocks, hidden power ice, earthquake, and explosion with possibly a groundium-z or icium-z.
Magearna
I want Magearna to be a bulky special tank with thunder wave to cripple ash-greninja and mega alakazam. I'm wondering if I should replace flash cannon with a more supportive move such as heal bell. I wanted to run volt switch for extra momentum and to easily switch out from checks. I ran flash cannon for steel stab for checking tapu lele and bulu. I am wondering if I should replace flash cannon for a better offensive typed move such as fleur cannon.
Rotom-W
I ran rotom-w as an offensive pivot to counter garchomp, landorus-t, and greninja with volt switch and hydro pump. I ran thunder wave once again to cripple fast sweepers. I was pleasantly surprised at how bulky rotom-w can be. I am wondering if I should change some EVs or change leftovers for something more offensive. Or perhaps I can just switch rotom-w with something more offensive such as Tapu Koko.
Mega-Alakazam
Mega-Alakazam is the main special sweeper for the team. I was able to easily KO 2+ mons with it. I am wondering if I should change anything in its moveset. Otherwise, I am very satisfied with how well Mega Alakazam performs in battle. I've seen huge sweeps with Mega Gardevoir as well. However, I still feel that Mega Alakazam outclasses Mega Gardevoir.
Tornadus-T
I haven't seen good performance with Tornadus. I feel that I need to change its moveset while keeping knock off and defog. I haven't seen much performance with hurricane and haven't been seeing much use for heat wave (basically I haven't seen much Kartanas or Ferrothorns). I feel that using a slot just for defog is not very efficient at all. I want Tornadus to have a better offensive set as well.
Ferrothorn
I decided to put a second, more physically defensive tank in my team. I chose Ferrothorn for its typing. I've been advised that stacking entry hazards is a good idea, thus running spikes. I ran leech seed and leftovers for recovery. However, I am still worried that this wouldn't be a sufficient enough recovery. I ran gyro ball with 0 speed IVs and a relaxed nature for maximum damage, and ran power whip for extra grass stab.