Easy Training?????

First like soraking11 says we can't tell if you don't tell us his team.
Second here are my recomendations:

Togekiss:get a modest nature togekiss cause that way his special ATK. Is way higher than normal but you sacrifice ATK. , this is okay cause his ATK. Status is low and special attack is very high, so teach him only special moves I recomend psychic,shadowball,aura sphere,air slash

Gallade:well get a adamant nature cause that way he has a higher ATK. But less Special ATK. This is also OK cause his Special ATK is very low, this way attacks like Leaf blade cause lot more damage, and teach him leaf blade,Psycho cut, Night Slash, And Brick Break, also make him carry a scope lens for a very high critical hit ratio, you will get criticals super frecuently, or make him carry a muscle band to boost his Physical attacks power. By the way Gallae is my favorite pokemon!

Magnezone: another wise Pokemon choise you know you chose good pokwmon with this it is the third. OK, get a mild nature one, to get a higher special ATK and less speed cause Magnezone has a low speed but vary high special atk, and with less speed gyro ball cause more damage!
Attacks: Thunderbolt, Flash Cannon, and other special attacks

Porygon Z: good special attack but low stats so get a modest nature for higher Special ATK. And lower ATK. Cause that is the best choise for this Pokemon cause it has a high special ATK. And low ATK, got it?
You chose good attacks except zap cannon cause it misses too much so switch it with thunderbolt

Electivire: great Pokemon super high ATK. Beter get a adamant nature to boost it ATK a lot more and sacrifice Special atk, This is because this way because it's special atk is not "great" OK? Teach him Thunderpunch, earthquake, giga impact, and another PHYSICAL ATTACK NOT SPECIAL MOVES!!

Change houndoom he is way too weak all his status are low better a infernape cause infernape has a VERY HIGH ATTACK, SPECIAL ATTACK, AND SPEED!!!but sadly low defense and special defense so if you get one teach him Earthquake, flame thrower, iron tail and blast burn( the strongest fire move wich is like hiper beam cause it also makes you recaharge) this way you have a very high posibility to KO him in one move! But you have to equip a muscle band or a wise glases to improve his ATK or Special ATK

And by the way to train in five minutes like that is possible with the INF. Experience cheat wich makes you reach LV. 100 with just one battle cause it makes you get infinite exp after you KO a foe, oh and the Pokemon I listed above make them carry muscle bands for those of high attack and a wise glasses for those of high special ATK. Thats all

If we don't know the opponents team, it is impossible to tell

Who cares

I don't care

Yes...it is possible to train a Pokemon up to lv 100 very very quick...by using action replay cheats...here is a cheat to get 65000 exo after a wild battle...and 98302 exp after a trainer battle...but the trainer battle one only works half the time and the wild battle works all the time...hold are when it says "the wild ______ fainted"

94000130 feff0000
621bfb0c 00000000
B21bfb0c 00000000
1000229c 0000ffff
D2000000 00000000

You have a very high offensive stat with your line-up, but a team of good defense good burn through your PP and leave you in big trouble, so yous PP ups and PP maxes, also, get a strong Pokemon like a groudon or kyogre, or any good defensive Pokemon, so incase he throughs out a very good defensive Pokemon out, through yours out, make sure he knows good moves and you use stat raising medicine on him, use muscle bands and scope lensesso you can get a hard hit more often, but good moves I would recomend are solar beam if you have a groudon with the drought ability, then the sun will come out and solar beam will hit asap, and if you have kyogre that has drizzle, teach him thunder, because when it's raining thunder will hit with a gurente, so you can get through his defence with hard hitting moves, I also have all 493pokemon and every move, so if you need a Pokemon, tell me the moves then put up a geodude for what ever Pokemon you need and I will send it to you, L100, post under my ?, if you need anything.

Another recomendation is, you have a team of 4 types, so you can be trumped with ease, so make sure each of your Pokemon know 2 good moves against type trumping so you will be able to keep your Pokemon alive longer.

1. Yes it's possible. With AR. Not recommended tho because of 1 you cannot ev train and 2 it's not as satisfying as when you finally reach 100. 2 it doesnt matter what you have or he hacks. It's what you or him do with them. If hes a good hacker though and he knows your team you are vulnerable.