Unlocks after complete the Scary Night map for the first time. PvP lets you battle against other player's army to earn gold and increase pvp points for monthly ratings reward.
Every win will +1 to your streak, and every 3rd win will earn you some other rewards according to your current win streak. Streak will reset upon lost.
A very easy way to get high streaks is by challenging weak enemies in Tournaments, as these duels count for PvP streaks.
It's advised that you befriend some player with the same/lower than your power rating and use the Ratings > Daily screen for easier wins. Guild battles do not affect PvP.
Attacking high player ranks with low battle power are more preferable based on the way battle power ratings are calculated, and the army size for player ranks. You will be attacking many weak creatures, opposed to a few super strong (and most likely AOE/splash heavy) enemies.
Streak rewards reclycle after 39th win (meaning the 42nd win gives the same rewards as 3rd and so on). Here is the rewards for PvP streaks :
|Streak||Gold||Glory||Shadow Soulstone||Juicy Meat||Other|
|15||15,000||450||1||---||1 Pal's Soulstone|
|21||30,000||600||2||---||1 Ruby Soulstone|
|30||75,000||750||3||1||1 Amber Soulstone|
|36||125,000||850||3||1||1 Fenix Amulet|
Rewards are given based on weekly/monthly rankings. Dark crystals (blue), allow you to summon elite shadows/hybrids/creatures.
Rewards are based on participants, so the following numbers can vary drastically.