I’ll give this a rate and it should not be too long since there aren't going to be any major changes to the team, I will try and keep it as close to your original team as I can. I don’t think that any pokemon need replacing as it seems like a solid team with not too many serious weaknesses, but moves and EV spreads can do with some tweaking. All the changes I am going to make are by my opinion and you don’t need to feel that you have to agree with me if you have had success with your previous EV spreads/moves. Changes will be in bold.
@ Mawilite
Ability: Intimidate ---> Huge Power
EVs: 228 HP / 204 Atk / 76 SpD
Brave Nature (-Spe, + Atk)
IVs: 0 Spe
- Play Rough
- Iron Head
- Rock Slide
- Protect
Mawile got a tweak in the EV spread so that it can survive max special attack Heatran’s heat wave, as well as making the most of each EV/stat point by giving it an even attack stat for Huge Power. Very similar to your original EV spread. I then replaced sucker punch with rock slide because your team does not have a very good match up against Charizard-Y and can’t hit it for much damage except stone edge from Hariyama. Under trick room you also get the flinch chance which can be critical in some situations.
@ Mental Herb
Ability: Levitate
EVs: 224 HP / 60 Def / 188 SpA / 36 SpD
Calm/Sassy Nature (- Atk/Spe, +SpD)
- Trick Room
- Ice Beam
- Psychic
- Helping Hand
I noticed that your team works much better with trick room up, rather than some semi-trick room teams that work just as well without trick room. So because of that I gave it a mental herb to stop those annoying taunts and guarantee trick room set up in most situations. I also gave Cresselia’s EV spread more purpose, everything it does is outlined here. If you can’t get your hands on a calm/sassy cress then you can use your original spread but put the 4 SpD EVs into Defense, it makes the most of every point you have.
@ Assault Vest
Ability: Guts
EVs: 140 HP / 228 Atk / 76 Def / 60 SpD / 4 SpA ←(These 4 EVs are wasted)
Brave Nature (-Spe, +Atk)
IVs: 0 Spe
- Fake Out
- Close Combat
- Stone Edge
- Knock Off
The moves themselves needed no changing since they work nicely with your team, but I did give it a new, more offencive, EV spread that I made a few months ago. Here are some calcs of what it can do:
Offensive:
- 228+ Atk Hariyama Close Combat vs. 252 HP / 4 Def Heatran: 198-234 (100 - 118.1%) -- guaranteed OHKO
- 228+ Atk Hariyama Close Combat vs. 252 HP / 0 Def Mega Kangaskhan: 210-248 (99 - 116.9%) -- 93.8% chance to OHKO
Defensive:
- 252+ SpA Choice Specs Pixilate Sylveon Hyper Voice vs. 140 HP / 60 SpD Assault Vest Hariyama: 200-236 (84.3 - 99.5%) -- guaranteed 2HKO
- 252 Atk Parental Bond Mega Kangaskhan Double-Edge vs. 140 HP / 76 Def Hariyama: 200-236 (84.3 - 99.5%) -- guaranteed 2HKO
@ Leftovers
Ability: Flash Fire
EVs: 212 HP / 252 SpA / 44 SpD
Modest Nature (-Atk, +SpA)
- Heat Wave
- Earth Power
- Substitute
- Protect
Heatran seems fine as it is really, although I slightly tweaked the EV spread since 212 HP EVs helps to get the most out of leftovers recovery. If you ever want to use leftovers/black sludge on a pokemon then make their HP stat 16n+1 (+1 of a multiple of 16). I was also thinking that you could change substitute into another attack. Such as maybe ancient power to help your charizard weakness, or flash cannon for extra STAB for fairy's and dragon's, or maybe even flamethrower for a 100% accurate fire type move.This is because you want to make the most out of your four trick room turns. If you do decide to do this then I suggest you switch out leftovers, max out your HP EVs, and let Heatran hold safety goggles to deal with opposing Amoonguss. As for the nature, modest should be fine but if you can get a min speed quiet Heatran then use it.
@ Sitrus Berry
Ability: Regenerator
EVs: 204 HP / 148 Def / 156 SpD
Sassy Nature (-Spe, +SpD)
IVs: 0 Spe
- Spore
- Rage Powder
- Protect
- Giga Drain
Honestly, I don’t know why more people aren’t using situs berry on amoonguss, it’s a bulky redirection pokemon isn’t it? Anyway, I gave your teams berry to make friends with the mushroom for extra longevity on the field. A ‘fast’ spore is very threatening under trick room, and also it will be able to redirect more moves. I also tweaked the EV spread from the same team that my Hariyama was on, here are calcs of what this can do:
- 252+ Atk Parental Bond Mega Kangaskhan Double-Edge vs. 204 HP / 148 Def Amoonguss: 180-214 (83.7 - 99.5%) -- guaranteed 2HKO
- 4+ SpA Mega Charizard Y Heat Wave vs. 204 HP / 156+ SpD Amoonguss in Sun: 182-216 (84.6 - 100.4%) -- 6.3% chance to OHKO (Most Charizards nowadays are more focused into bulk, so there are lots of modest 4 SpA ones)
@ Choice Specs
Ability: Pixilate
EVs: 252 HP / 4 Def / 252 SpA
Quiet Nature (-Spe, + SpA)
- Hyper Voice
- Shadow Ball
- Psyshock
- Hidden Power (Ground)
I know it’s going to be hard but try and get hidden power ground on your Sylveon because your team has a bad and unfavorable matchup against Heatran. I also gave it choice specs to KO, or at least do very big damage, to the fire/steel type just mentioned. The specs also does more damage than the pixie plate with all your moves, and with a trick room up you want to make the most of your four turns by doing the highest damage possible. If you can, getting a quiet nature would help you out, as well as 0 Spe IVs. Well, all your pokemon should have speed decreasing natures and 0 Spe EVs if you can.
So those are my possible improvements to the team, if you don’t agree with any of them that’s completely fine and you can carry on using your original team if you are having success with it.
Most of the improvements I have done are about EV spreads, I think that you’re good at building teams, although you need to watch out for some pokemon which your team has bad matchups against and recognise them as a threat.
I think that you need to learn more about the EV mechniques, as you were wasting a few EVs on your pokemon when it could have been avoided, one more stat point can change the course of a battle. Learning to make purposeful EV spreads which fulfil certain roles is also a skill to learn, rather than just adding some random Def/SpD if you want some bulk. If you want to do that I suggest adding enough Atk/SpA to OHKO/2HKO certain pokemon then adding the rest in bulk.
You can use the damage calculator to make your own EV spreads and to see if you are wasting any points.
Hope This Helps.
Zorua0