No boring exposition for this RMT, I'll cut right to the chase.
After plugging your team into Team Magma Teambuilder, you have a barely sustained Flying weakness and a rediculous Fire weakness. Heatran alone can't hope to absorb every Fire attack, plus your Water weakness becomes prevelant once the Sun goes down, plus a strong Ground weakness. I'll try not to change too many Pokémon, but rather majorly tweak most of your sets. Changes will be in bold.
Mega Charizard Y
Charizard @ Charizardite Y
Timid | Blaze
252 Spe / 252 SpA / 4 HP
- Heat Wave
- Solar Beam
- Protect
- Tailwind
I had a few choices to make when revising this team, but the most stable one seemed to be forming a Tailwind team around Breloom. Hence, Mega' Zard becomes one of your Tailwind setters. Protect is necessary in VGC. About your old set, DDance is only really seen on Salamence and Gyarados in VGC. Charizard is far too vulnerable to try setting up. Earthquake is possible on surprise sets, but has no place on Tailwind 'Zard.
Aegislash
Aegislash @ Weakness Policy
Quiet | Stance Change
252 SpA / 252 HP / 4 SpD
- Flash Cannon
- King's Shield
- Shadow Ball
- Wide Guard
Wide Guard is the real selling point of Aegislash, and it compliments your team wonderfully.
- Blocks Heat Wave for Lucario, Breloom, and itself.
- Blocks Earthquake for Lucario, Heatran and itself.
- Blocks Rock Slide for Charizard.
- Blocks Icy Wind and Snarl.
Physical Aegislash is a joke in VGC due to the obscene amount of Intimidate and Burns (NOTE: Substitute + Sacred Sword mixed Aegislash is perfectly viable, but not for your team). That is why I added Shadow Ball for STAB, as well as providing a way to deal with Gengar, Cresselia and Gothitelle. The EV spread was optimized for bulk and brute force.
Tangela --> Togekiss
Togekiss @ Sitrus Berry
Bold | Serene Grace
252 HP / 60 SpD / 196 Def
- Tailwind
- Follow Me
- Air Slash
- Thunder Wave / Protect
Tangela, while cool, is hindering to the team's Birdspam weakness. Since the focus is now Tailwind, Togekiss is now the prime redirector. Tailwind is obvious, giving you a nice second alternative to Charizard. Follow Me is to redirect incoming attacks. Air Slash is for obvious flinch hax. The final choice is either Thunder Wave for speed control and paraflich hax or Protect for scouting and surviving.
This EV spread of my own design survives:
- Double-Edge from Mega Kangaskhan and Mega Salamence
- 3HKO from 252+ SpA Aegislash's Flash Cannon
- Iron Head from Adamant Bisharp
- Various Rock Slides
- Most Lapras' Freeze Dry and most Ludicolo's Ice Beam
Breloom
Breloom @ Focus Sash
Jolly | Technician
252 Atk / 252 Spe / 4 SpD
- Mach Punch
- Spore
- Bullet Seed
- Protect
Nothing to change about Breloom. I just want to say how brutal Breloom is under Tailwid. It becomes even more evil with Follow Me and Wide Guard.
Mega Lucario
Lucario @ Lucarionite
Inner Focus | Jolly
252 Atk / 252 Spe / 4 Def
- Protect
- Bullet Punch
- Close Combat
- Ice Punch
Inner Focus over Justified so that you can OHKO Mega Kangaskhan on Trun 1 without fear or Fake Out flinches. I could suggest HP Ice and a bit of Sp. Attack investment over Ice Punch due to the omniprescence of Landorus, but Lucario is better suited for the late-game and has priority Bullet Punch, so I'm not too worried.
Heatran
Heatran @ Shuca Berry
Modest | Flash Fire
244 HP / 252 SpA / 12 Def
- Heat Wave
- Ancient Power
- Protect
- Earth Power
Not much to change here, either; only Earth Power to help your team handle opposing Heatran better. You already have two Steel STABs in Aegislash's Flash Cannon and Lucario's Bullet Punch, so Flash Cannon is the most logical move to toss. I run Ancient Power Heatran myself, and sometimes the surprise Talonflame and Charizard KOs are handy (plus you don't get walled to pieces by Thundurus).
The foundation of the team is solid. However, some of your original movesets aren't the best, and do not fit with the team. I really hope these changes help to capitalize on this sturdily-built team's strengths and counter its weaknesses. Have fun with VGC!
