My 2DS won't let me message @Uria11 to give him feedback, so I'll post my thoughts here.
Your competitive team
Trevenant is fine, just watch out for Gastro Acid.
Blastoise needs 252 SpAtk 252 Speed 6 HP. Replace Flash Cannon with Aura Sphere and replace Water Pulse with Hydro Pump.
Weavile's stats are fine, but replace Shadow Claw with Fake Out, ditch Brick Break for Fling, and replace Ice Shard for Ice Punch for accuracy or Icicle Crash for power.
Skarmory is fine, but ditch Rock Slide for Stealth Rock.
Magnezone needs HP Fire. Magnet Pull > Sturdy An Air Balloon is strongly advised.
Dragonite needs Lum Berry. Ditch Dragon Rush for Outrage and ditch ThunderPunch for Earthquake. Watch out for Fairy-type Pokémon, though. spunky07216 - 3 weeks ago
I'd be able to offer my own perspectives and such, but you should at least link to his original team and builds so that we might get some perspective on where your critiques are coming from. For example, Dragonite in general doesn't "need" Lum Berry; Weakness Policy builds can be extremely useful, if played right, and other builds based around other more offensive items can work too. So for the proper perspective, it'd help to see the original team. Eevee-Trainer - 3 weeks ago
The question creator posts what are called "Additional Details;" people who are answering the question post what are called "Clarification Requests."
No different than comments either way.
That said, you can still copy and paste links through the 3DS/2DS browsers - I've done it before, even if it is a pain in the ass. Eevee-Trainer - 3 weeks ago
Or even just telling us *where* to find the team - what board or topic or whatever - would help. (The more specific you could be the better.) Eevee-Trainer - 3 weeks ago
By the by, you realize that the @ notifications only work on the boards, yeah? Thard_Verad - 3 weeks ago
I can't link to his team, because I'm using the 2DS Internet Browser.
Also, you posted a Clarification request. I thought only the topic's creator can post there. spunky07216 - 3 weeks ago
He actually posted in the answers section. His question was already answered, but I'll try to find his link. spunky07216 - 3 weeks ago
This question was asked in the last 60 days with no accepted answer.