On 9 February 2016, Siovas in a winning 1–0 matchday against fierce rivals PAOK, reached 100 appearances with the club's jersey in all competitions, having the amazing undefeated percentage of 89%, one of the largest among Olympiacos players.

[12] On 19 June 2017, Siovas signed a permanent four-year deal with Lega, for a fee believed in the region of €3 million, whereas Olympiacos keep a 15% resale percentage.

[16] On 1 February 2018, after the epic Copa del Rey qualification against giants Real Madrid Leganes scraped a 1–1 draw at home to Sevilla FC in their first leg semi-final matchup with the Greek defender scoring the only goal for his club.

The Greek defender took full advantage of poor goalkeeping from the Sevilla custodian to head home from close range in the 56th minute canceling out Luis Muriel’s early goal.

[17] On 19 May 2018, in the last matchday of the season, he scored by cleverly controlled possession and slotted beyond stranded goalkeeper Pedro López, after an assist from Ezequiel Muñoz in a 3–2 home win game against Real Betis.

[18] On 1 December 2018, he scored his first goal for the 2018–19 season, with a header after a corner from Óscar Rodríguez Arnaiz, giving the lead in a 4–2 away win game against Real Valladolid.

The study by CIES pertained to Europe’s top five domestic leagues specifically and Siovas has won a whopping 105 aerial duels, losing just 23.

On 1 December 2019, Siovas suffers a severe bruise with hyperextensin in his left knee in the 5th minute of an away La Liga game against Sevilla FC.

[25] On 7 March 2021, Siovas scored an early equalizer in 14th minute, but Celta delivered a resounding 4–3 victory against his club effort to avoid relegation.

The Spanish career played a vital role in the January transfer window to receive two offers from Segunda División clubs, namely Girona FC and Málaga CF.

[34] On 6 September 2020, Siovas escaped his marker inside the box, expertly collected Dimitris Giannoulis’ searching pass, twisting to a shooting position and turning his effort beyond the goalkeeper, helping Greece to take a two goals lead in a final 2-1 away Nations League win against Kosovo.

[36] On 20 April 2021, in an interview for a Greek sports broadcaster, he openly declared that he wouldn't return to the national side under the Dutch manager's reign.