I can't decide what regi to choose, as I think you can only get one per save file. So I want to know which one is better.
It's a little soon to be able to tell which will perform better competitively. However:
Regieleki is the frailest of the Regis but also the fastest. You can hit like a truck and outspeed pretty much anything in the game within reason, all while having access to Thunder Cage, which is a multi-turn Electric-type attack that’s 80 base power and can’t miss.
Regidrago sacrifices speed for HP and has the same defenses as its Electric-type sibling. You’ll hit just as hard with the Dragon-type and its signature move does more damage the higher its HP is.
Source
Regieleki's base 200 Speed Stat immediately stands out, and it is now the fastest Pokemon in the game - beating Deoxys' Speed Form base 180 Speed Stat and Ninjask's base 160 Speed stat. It also boasts respectable base 100 Attack and Special Attack, making it a potentially good sweeper.
Regidrago has high base 200 HP, which is just fifty five points lower than Blissey. Despite this, it has low defenses which means it may have a difficult time taking hits despite its high HP. Fortunately, Regidrago has a great 100 base Attack and Speed. It can also learn Dragon Dance, which means you can use this legendary titan as a bulky setup sweeper!
Regidrago has high base 200 HP, which is just fifty five points lower than Blissey. Despite this, it has low defenses which means it may have a difficult time taking hits despite its high HP.
Fortunately, Regidrago has a great 100 base Attack and Speed. It can also learn Dragon Dance, which means you can use this legendary titan as a bulky setup sweeper!
It seems like Regieleki is a more immediate attacker, while Regidrago needs a bit to set up first. Regieleki has a terrible movepool, but it does get a few fairly solid moves. Regidrago has a bit more variety. If you're simply choosing one from an in-game standpoint, choose either, it doesn't really matter in-game.
Hope I helped!
