The Returning User Reward or the WIll of Fire requires you to reach Lv30 or Lv35 first to be eligible to have this kind of Returning Rewards .. Your Account must be offline for minimum of 7 days to trigger the said Rewards .. The Rewards (Exp and Cps) are determined by your level, the rewards varies for each level bracket .. And from what i've heard from other people, this Rewards has a cap of 1 month ..

I have no idea how much coupons you can earn for a month, but one of my account (lv83) was offline for a week and got 800+ cps when i opened it back .. The exp gain was around dunno the numbers but my char was lv82 that time with 80% exp, after getting will of fire, i ended up leveling up to lv83 with 28%ish exp ..