>>45462169Under electric terrain, Raichu is actually faster than Regieleki. Not even by a small amount, either, it's over 100 speed faster. It's so fast it outspeeds unburden Hawlucha. In fact, I'm pretty sure it's the second fast Pokemon theoretically, behind only Barraskewda, reaching a top speed of 2,800 after 3 agilities, as opposed to Regieleki's cap of 2,192.
That's not the reason it's so good, though. Or, not the only reason. It also hits like a truck. Regieleki is factually harder hitting on the Electric side, but A-Raichu has Focus Blast, Psychic, Grass Knot, and Surf for coverage, and it has Nasty Plot to help it set up even more. It hits so hard after a Nasty Plot that it can very consistently kill the most common Landorus sets with Psychic, a Pokemon that would normally fuck Electric-monos up.
>+2 252+ SpA Raichu-Alola Psychic vs. 0 HP / 0 SpD Landorus-Therian: 313-369 (98.1 - 115.6%) -- 87.5% chance to OHKO 