Looking at the Gyarados from Stormfront, one can easily see that this monster will have to be built– I mean, 5 energies?! Even for 100 damage and the possibility to rob an energy from every opponent's pokemon, it's a steep price. Even with Garaydos' 130 hp, it can't sustain hits forever, so your options are to build it up on the bench or--- but, wait a minute! The first attack costs nothing, and does 30x for every magikarp in the discard.
Well, this allows us to use a bunch of supporters. Make sure to have one magikarp and Garaydos in your hand first, but then you have some options to get magikarp in your discard without giving your opponent a prize card.
- Felicity's drawing: discard up to two cards in your hand to draw 4 cards. This allows you to put extra magikarp directly to the discard, and still have draw power.
- Volkners' Philosophy: discard a card in your hand to draw 6 cards. Same strategy as above.
Hopefully, if you can get magikarp into the discard fast enough, when you pull out the Garaydos, you have 30 to 90 damage right off the bat, with no prior build up! This will allow you to build up something else on the bench without Garaydos hogging all the energies. This makes him much more potent, and putting the magikarp in the discard puts you in no worse position.