It will have some new rules: if you stay close to your partner your skills will be recharged faster, but if you move away from the enemy they will be able to see your location, but as the game tries to fight your enemy with your partner, these rules do not They will be more complication.
And if you still have no idea what partner to have, do not worry, Crimson Days will allow the creation of couples, Bungie has also increased all the value rewards in all the Crucible modes during the event.
If you're not in PvP you can join using the rewards that Lord Shaxx sells, plus they will play an important role in getting the rewards on Crimson Days.
Last year you had to win the challenges to receive some items, this year you can win Confectionery Hearts by getting rewards and winning Crucible games, winning games gives you 7 hearts, if you lose you will receive 5 and complete the daily rewards between 15 and 75 , this will allow you to compare the items that Shaxx is selling:
Warmhearted Gift pack for 15 hearts. (New article)
Strip Legendary Ghost Shell, for 25 hearts.
Flaunting Dance Legendary emote, for 150 hearts.
Exhausted exotic sparrow, for 50 hearts.
The Vow Legendary bow, for 100 hearts. (New article).
And Wardcliff Coil Dieselpunk ornament, for 125 hearts.
Of the new items, The Vow is the first arc for non-renegade players and the Warmhearted package that can have mod and upgrade cores, but these will not be the only new items.
The Shaxx loot group can access all the elements in the Crimson Engrams of the event, if you get all the triumphs of the events available in Crimson Days you can get a Ghost chocolate shell.