[Skore]

I'd like to propose Ice/Fighting

One of the riskiest things you can do in today's metagame is have an Ice type on your team with it's myriad of weaknesses to common STABs, SR and 2 of the 3 most seen priority moves while having a great offensive STAB yourself. But unfortunately no matter how good your defensive stats are, hard hitting super effective moves are all too common in the BW2 meta and it's why only exceptional Ice Types backed by a favorable secondary type manage to break into OU.

On the opposite side of the coin, Fighting also offers super offensive STAB with some nice resistances which would help shore up some of Ice's multiple weaknesses while still leaving it vulnerable to the same priority moves it has always been vulnerable to, turning other weaknesses into neutrality and adding a few weaknesses that Ice types have never had to fear before.

Both STAB options offer a good variation of moves on both the Physical/Special side to work with which is a good way to keep options open.

Edit: Now I've stakes my claim I'll add some of the points BMB made:

Passive damage weakness – This combo would be neutral to SR, take no damage from hail but SS, T-Spikes burns etc would still affect it. Resistance to U-Turn does help by giving it opportunities to switch in but doesn't automatically equal a sweeping opportunity.
Good overall STAB combo – 2 very good STAB options offered but both have resistances allowing an opponent with good prediction to get a switch in and ruin your day.
Lots of weaknesses and resistances – Many. Weak to Steel, Fire, Fighting, Psychic and Flying while resisting Ice, Bug and Dark attacks which creates opportunites to switch in but leaves enough risk to be caught by a good prediction from your opponent.
STAB on notable risky moves – Blizzard and Focus Blast are 2 inaccurate moves on the special side, while on the Physical side you have Focus Punch, Cross Chop, Avalanche and Icicle Crash. Icicle spear is another gamble without Skill Link.