Warp > Cyclone. I don't know why people are playing Cyclone instead. Gyarados almost always has a Crobat G (which ahs free retreat) on the bench so warp is a cylone energy at worst, but also serves as a way of switching (e.g. out of sandtomb lock or if you have a regi trapped active).
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I'm still noob, but imho warp energy is not doing anything to defending pokemon, while cyclone moves your active. So if you have wrong pokemon locked you need warp energy and if you need move your opponent's pokemon you need either cyclone or regice, byt regice can be power sprayed/locked. IMHO it is hard to say which one is better. If you are facing flygon/luxray combo I assume you need more warp energy/SSUs. If you are facing opponent who can power lock then you need more cyclone energy. Am I right in my assumptions?
And do you combine your cyclone energy with warp points or switches?
Back to regice/registeel. So unless you are facing abomasnow/tyranitar/snipers/spread dmg regice looks a little bit better as it provides the effect of cyclone energy.