I'm going to get this out of the way: PvP custom matchmaking
players would be able to make a custom game where they would be able to do the following:
-set map/ map rotation
-set point goal
-set time limit
-make the game private(guild or friends only) or public
-set player count(teams of 4, 5 or 6)
-invite people to the game/people can join you

New PvP game modes, or the Krogmosseum/Koloseum modes:
These game modes would work differently than the current modes:
-new currency(Kolosseum tokens)
-used to buy cosmetic items such as costumes, accessories and recipes(reskins of existing weapons, like the scissor blades)
-no class abilities
-no bomb-heads
-spectators(would be nice for all PvP modes)

Mode 1: Gladiator: http://imgur.com/6UKFl
The game will consist of 8 players who are dealt random gear(helm, armor, shield and 1 weapon) and 2 random vials/pills
depending on the tier they entered. players are then sent into the arena where they have a free for all, while this is happening mobs are released from the cages and attack the players, mobs will have a chance of dropping hearts. Special enemies may also spawn randomly in place of a normal mob wave(return of tortodrone? vog/skolver/snarb cubs? lowly trojans?) if killed the mob will drop an item that who ever gets to it first will be invulnerable for 5 seconds. There would be 3 prizes: 1st, 2nd and 3rd
1st will receive 4 koloseum tokens and 3 krogmo koins
2nd gets 3 koloseum tokens and 2 krogmo koins
3rd gets 2 koloseum tokens and 1 krogmo koin
all other players get 1 koloseum token
in addition, in place of the bribe system there will be a bet system where you place a bet on the character you think is going to win(1st place)
if they do win you will receive double your bet(up to a certain amount) and 1 koloseum token. If they don't get 1st you loose your bet and get nothing
but dissapointment.

Mode 2: unnamed:
You get to choose your weapons from the koloseum armory [normal damage weapons with no UVs... one for each type of weapon(2 swing, 3 swing, DVS style, 2 shot, 3 shot, automatic, ect.)]
The Koloseums dividers go up and 2 teams of 4 have to fight wave after wave of enemies. Whichever team wipes first looses and receives 1 of each token. the winning team gets 3 of each. This mode would be more of a competition as neither team can interfere with each other.

Ideally there would be a third game type but i cant think of one...