If your Raichu is left with the Daycare couple and reaches level 100 it will run away. The couple will give you Pikablu as compensation, and you can find your former Raichu evolved at the Power Plant. You have to catch it again.
Badge Case [Time Badge] StrifeHart is my OTP. services performed at BSC: 2 Riley's Boyfriend on the Pokemon BW2 & X boards. W1 FC: 4170 0917 6393