Does Demonblade Tryndamere have Aatrox (the sword)

No, the Sword doesnt look like the Sword of Aatrox... and the Sword IS Aatrox, so, is one of those things that doesnt change in shape when the Darkins take a host.

Demon Blade Tryndamere is a non canon thiller movie, nothing more.

The skin was made ages before Darkins were even thought of. Unless Tryn gets updated and the design gets reimagined (very likely to be what happens in the future), I don't think the skin has any connections to League or Tryn other then being a really cool idea.

It be a cool alternate reality if tryn kills aatroxs current owner and takes the sword. And demon blade tryn is fighting the darkin slowly taking over his vody.

Currently no,but I imagine that once Trynda receives a visual update(though it's likely going to take a few years before that) they'll change it,so that he does actually use aatrox.