Starmie Hiddenpower

So my Starmie got Hiddenpower as a psychic move and got psychic! I will try out later. But i think it got STAB on the Hidden Power. Should be pretty nice :D. Two Water type moves could be really awesome! But since Starmie is not a good defender i think in this case aquagun could be better!

Of course yes.

on offense, water gun would always be better than a water-type hidden power. on paper they have the same dps, but because of how the damage formula works, which rounds down and then adds +1 damage to every move, 3 water guns will always do more damage than 1 water-type hidden power, and have the exact same energy per second and cooldown.

so lets say your water gun does 3.2 damage, that gets rounded down to 3, and then +1 for 4 damage, multiplied by 3 means the defender loses 12 hp. whereas a water hidden power would have 9.6 damage which gets rounded down to 9, then +1 for 10 damage, and both would gain the exact same amount of energy (15) in the same amount of time (1.5s)

psychic hidden power can be better than water gun on offense if water gun is resisted but not by much, and is only better compared to 3 water gun usages. if you dodge every move and you're able to get 4 or 5 water gun uses between each dodge but don't have enough time to get a second hidden power then water gun still does more dps even if resisted compared to psychic hidden power.

on defense hidden power's better even when resisted, because of it's higher energy and damage per use, which is what matters most since defender's use their moves slower, although starmies dont make great defenders due to their low stamina.

so basically water gun is better.