NXT UK (2020–2022)

Cusack was reported to have signed with WWE on 20 January 2020, now operating under the ring name Aoife Valkyrie.^[1] Valkyrie competed in her first match on NXT UK on 17 January 2020, defeating Amale. She then defeated Isla Dawn the next night on 18 January 2020, and defeated Amale again on the same night. On 26 March 2020, Valkyrie defeated Nina Samuels.^[7]

In February 2020, Valkyrie toured with WWE's US-based NXT brand for the first time, wrestling on two house shows in Florida. Valkyrie defeated Aliyah on 14 February in Tampa, followed by defeating Jessi Kamea, MJ Jenkins, and Taynara on 15 February in a six-woman tag team match at a Fort Pierce house show, where she teamed up with Mia Yim and Rita Reis.^[7]

Valkyrie made her return to television on the 17 September 2020 episode of NXT UK in a winning effort against Isla Dawn, and on 29 October 2020 she competed against Dani Luna, again in a winning effort. Valkyrie remained undefeated until 29 April 2021 when she lost to Meiko Satomura.^[8][9]

NXT and Women's Championship reign (2022–2024)

Valkyrie remained with NXT UK until its closing in fall 2022, then moving to the U.S. later in the year to wrestle in NXT under the ring name Lyra Valkyria. On 13 December, Valkyria made her debut on NXT, defeating Amari Miller.^[10] On the 21 March episode of NXT, Lyra beat Ivy Nile to qualify to the Ladder match for the NXT Women's Championship at NXT Stand & Deliver,^[11] though she didn't manage to win the title at the event.^[12] On the 9 May episode of NXT, she beat Kiana James to advance to the semi-final of the tournament for the vacated NXT Women's Championship.^[13] On 23 May, she also defeated Cora Jade to advance to the final, facing Tiffany Stratton at NXT Battleground, where she ultimately lost.^[14][15] However, she earned another opportunity at the championship by securing a victory over former NXT Women's Champions Roxanne Perez and Indi Hartwell in a triple threat proposed by champion Becky Lynch on the 3 October.^[16] Earlier in the show, Valkyria noted she was inspired by Lynch's NXT debut and remarked on the elder's impact on Irish wrestling.^[17] Valkyria bested Lynch to win her first NXT Women's Championship at Night 1 of NXT: Halloween Havoc.^[18] On the 21 November episode of NXT, Valkyria successfully defended her title against Xia Li in her first title defense.

On 2 January 2024, at NXT: New Year's Evil, Valkyria successfully defended her NXT Women's Championship against Blair Davenport.^[19][20] After their match, Lola Vice tried to cash in her Breakout Tournament contract, only to be stopped by Tatum Paxley, who was obsessed with Valkyria since December 2023.^[20][21] At NXT Vengeance Day on 4 February, Valkyria successfully retained the NXT Women's Championship against Perez and Lola Vice, who cashed in her Breakout Tournament contract while the match was in progress to make the match a triple threat match.^[22] On the 20 February episode of NXT, Valkyria defended the NXT Women's Championship against Shotzi. During the match, Shotzi suffered a torn ACL and Valkyria won by referee's decision. NXT General Manager Ava announced an open challenge for the NXT Women's Championship match, which Lash Legend answered. Valkyria successfully retained the title against Legend.^[23] At NXT: Roadblock, Valkyria and Paxley faced The Kabuki Warriors (Asuka and Kairi Sane) for the WWE Women's Tag Team Championship as a reward from Valkyria to Paxley for the latter not interfering with the former's title matches in the previous week but failed to win the title after Valkyria inadvertently kicked Paxley. After the match, Perez attacked Valkyria and injured her arm.^[24][25] Valkyria returned and attacked Perez two weeks later, and a match between Valkyria and Perez for the NXT Women's Championship at NXT Stand & Deliver was made official where she lost the title to Perez by submission, ending her reign at 165 days.^[26][27] On the following episode of NXT, Paxley turned on Valkyria while saying that the title does not belong to Valkyria anymore.^[28] On the following week of NXT, Paxley revealed that her obsession with Valkyria was only because she had the NXT Women's Championship. Later that night, Valkyria attacked Paxley after her match, and NXT general manager Ava announced a triple threat match for the NXT Women's Championship involving Perez, Valkyria and Paxley at Spring Breakin', where Valkyria failed to win the title in her final match for NXT.^[29][30]

Raw (2024–present)

At Night 2 of the 2024 WWE Draft, Valkyria was promoted to the Raw brand.^[31] On the 6 May episode of Raw, Valkyria made her on-screen debut saving the Women's World Champion Becky Lynch from a beatdown by Damage CTRL's Dakota Kai, Iyo Sky and Kairi Sane, and at the same time would make her in-ring debut against Kai in the first round match of the Queen of the Ring tournament, where she emerged victorious.^[32] In the following week, she defeated Zoey Stark to advance to the semi-finals.^[33]