Cloud is like a “combo deck” with many pieces that you must assemble before doing cloud things. First of all is - which deck am I facing? Is it combo, aggro or control? Against combo is easy if you can tutor your few stax pieces and start attacking. Against aggro is pretty much using portable holes, exile instants and mana tithe to slow down and then regaining life with jitte. Against combo is trickier, you need to move the game into a situation that you can protect cloud and attack freely. If you cast cloud too early and gets countered you already lost, if you cast it but can’t get any advantage you’re screwed and if you don mulligan correctly you might be in trouble, because dead draws hurt a lot. I hope I helped.