Mr Williams, 25 and from Cheslyn Hay, died after a collision involving a van and car on the A5 near Lichfield in the early hours of Saturday morning.
Pedestrian Mr Williams was pronounced dead at the scene after the crash happened on the eastbound carriageway, between Muckley Corner and Wall, at around 12.25am.
A man and a woman from Walsall were arrested in relation to Mr Williams' death but have both been released as the Staffordshire Police investigation continues.
The university graduate and former rugby player's family have now released a tribute to him, saying he "could light up any room that he walked into".
It comes as donations continue to be paid to a fundraising page set up for his family which has raised more than £9,000 in less than a week.
A statement from Mr Williams' family said: "Ethan was a happy-go-lucky soul.
"Nothing ever got him down and we have struggled to pick any occasion when he didn’t have a massive smile on his face.
"He was a sportsman and a born leader who captained his rugby teams at Cheslyn Hay High School, Willenhall and Lichfield.
"Ethan was an adventurer and since finishing university in 2015 travelled extensively through Thailand and Australia, making many lifelong friendships along the way.
"We struggled whilst he was away as we felt everyone else was enjoying his massive personality, we were so happy when he eventually came home to us.
"We are so proud of how he could light up any room that he walked into, bringing people together, creating an open warm environment that people relaxed in.
"Ethan was currently making big plans for his three-month-old nephew, Albie.
"He doted on him and any conversation that you had with him involved what he was going to do with Albie him for Albie.
"It will be heartbreaking that Albie will only have pictures of his fantastic uncle, but we will make sure he never forgets him."
The family have also appealed for information relating to a watch that Ethan wore which was not found after the incident and holds "great sentimental value".
They added: "We have received hundreds of messages from around the globe, testaments to his charismatic, caring and thoughtful personality.
"He has left a massive void that can never be filled, not only in our lives but everyone who has had the pleasure of meeting him. Quite simply – he was a legend.
"Ethan's watch, a Tissot with a black leather strap, was not on his person at the time of the incident. As it holds great sentimental value, his family would like to recover it."
A 41-year-old man from Walsall was arrested on suspicion of causing death by dangerous driving and a 37-year-old woman, also from Walsall, was arrested on suspicion of perverting the cause of justice.
Both have since been released under investigation pending further inquiries.
Anyone with information relating to the watch or crash is asked to call Staffordshire Police on 101, quoting incident number 1 of November 16. Alternatively, call Crimestoppers anonymously on 0800 555111.
To donate to the fundraising page in memory of Ethan, visit www.gofundme.com/f/scobe.