Hearthpwn

I left out 1 Steam Surger, 1 Bonfire Elemental and 1 Meteor, and replaced them for 1 Fire Fly, 1 Lesser Ruby Spellstone and 1 Chief Inspector to destroy enemy secrets. I'm low-ranked (16), but won my first 7 games with it so far - thank you! :-)

what i can replace for Blazecaller

Why Meteor instead of Flamestrike though?

I don't really think Flamestrike or Meteor would be good in this kind of deck at all since they're both too slow. Just run stuff like Amani Berserker or card draw like Aluneth and a second Arcane Intellect so you can actually maintain board pressure and have a window to play your big elementals so they stick.

To find these decks, we looked for players that have been doing well, and picked out some builds from amongst the top performers. We only selected decks that were played in 50 or more games at Legend level

https://playhearthstone.com/en-us/blog/21867879/off-meta-report-june-12-2018

The elemental sinergy is really struggling,since only Water Elemental can activate it

Yes, I think Steam surger is only good if tempo played on turn 4, so I would replace Water elementals with some cheaper elementals, for example Fire fly.

What rank has this percentage?

Hard to say, but I'm assuming the author doesn't only play this deck since it has only a 54.2% winrate which isn't particularly high. I'd assume it's played between ranks 5-10 cause I don't really see this deck making it too high because it'll straight up lose to hard control like priest and mage and get steamrolled by faster decks like aggro mage and odd baku paladin.

It is in the legend ranks, And the deck is not bad, it is not too slow either.