Deformers

I found a fairly easy but time consuming way to level up. It requires two players and two controllers on each Xbox One. Load up the 2nd controller as a guest, go into Team Death Match and both load up at the same time. Once you start the match, one team leaves the match (press the button and hold on the Leave icon). It nets the other team 1140 XP and 210 prestige points. Each time takes about a minute. It should take about 200 matches each to get the full XP needed to reach level 20 and fully prestige or about 8 hours total. I did this yesterday for a couple of hours and got to level 7 and almost to the 1st prestige. This game will be closing soon, so I hope this helps those trying to finish.
If this helped, please give me a positive vote. If giving a negative, please let me know so I can fix it.

EDIT:
I started paying attention at level 7, so if anyone knows the XP for lower levels, let me know.
These are to level to the next level.
Level 7 6,000XP
Level 8 7,000XP
Level 9 8,000XP
Level 10 9,000XP
Level 11 10,000XP
You get the point.
Level 20 19,000XP

You start out at bronze level, which is a red diamond around your emoji for the level. To Prestige, you must get 5 stars per Prestige. Each Star is 1000 Prestige points. I got the first Prestige around half way through level 7.
Once you get your first Prestige, it adds two dots on the side corners, The next prestige adds an extra line to the top of the diamond, another 5 stars adds wings and a third dot at the top of the diamond. Somewhere around level 14, it goes to silver.
Silver has a silver diamond and has the winking face in the center of the diamond and you have to go all the way through the prestige levels again to get to gold.

Prestige happens in seasons. The first season ends in June 2017 with no set end day yet.
After each match, you get normal xp and prestige xp. You need 1000xp to rank up once. There are 20 bronze ranks and 20 gold ranks meaning you need 40,000 prestige xp for this achievement before the prestige season is over.

You will get about 125 xp for doing almost nothing in a match and about 350-410 for being first place, getting kills, and breaking things on the map. (These numbers are from boosting and may be different in a full match.)

This can be easily boosted with a 2nd controller. Search for public deathmatch until you get a lobby with only you and your other controller in the room and press X on each controller. This locks the lobby and nobody else will join you. Now just kill your 2nd controller for 3 rounds and repeat. Make sure your 2nd controller does not idle over 60 seconds or you will get booted.

This is long and boring, but not hard. Just make sure to work on it as much as you can so that you get your achievements before the season ends or you will have to start over during the next season.


*A side note: I was almost rank 14 in normal xp after just boosting this achievement, so that will take longer, but that xp will not be reset.


EDIT: It looks like 2 controllers on one console cannot start a match anymore. You can start one with 2 people on different consoles.