He played college basketball for the San Sebastian Stags, where he gained a reputation as one of the best amateur shooters in the country.
[2] After participating in the Junior NBA program did he finally get to play for the San Sebastian Staglets.
[6][7] In the 3-Point Shootout during All-Star festivities, he made it to the final round before losing to San Beda's AC Soberano.
[11] In Season 93, after their opening loss to San Beda, Ilagan contributed nine points and seven rebounds in a win over Arellano.
[13] With a shot for a Final Four spot on the line, he had 23 points and five rebounds in a blowout win over the Perpetual Altas.
His teammates Michael Calisaan and Ryan Costelo then scored big in the fourth-seed playoff against Letran to officially make the Final Four for the first time since Season 89.
[23] The NCAA also forfeited the Stags' two wins in the first round in which he played in, which sank them to the bottom of the standings.
[20] They opened the season with a 31-point blowout victory over JRU, with him leading the team with 25 points built on five treys, to go with five assists, three rebounds, and two steals.
[34] In that game, he had cramps for majority of the second half, but he fought through it and led a rally from 17 points down to just a one-point deficit.
[43] Ilagan made his PBA debut against the Blackwater Bossing, in which he had eight points on a perfect 3-of-3 from the field including two threes in just under two minutes.
[48] Before the start of the 2022–23 PBA season, Ilagan re-signed with the Converge FiberXers, the franchise that had acquired Alaska, on another one-year deal.
[51] On his team's next possession, he had the chance to make it a three-point lead with two free throws, but he missed both shots.
[52] TNT guard Jayson Castro was able to win the game for his side on a layup over Ilagan, and Converge sealed their fate by turning it over.
[53] He then led Converge to its 2nd straight win a new PBA career-high of 20 points against the NorthPort Batang Pier.
[56] On January 3, 2023, Ilagan, along with Michael DiGregorio and Tyrus Hill, was traded to the Blackwater Bossing for Barkley Eboña and a 2022 first-round pick.
[58][59] In a 2024 Philippine Cup win over TNT, Ilagan stepped up for an injured Rey Nambatac and had a near triple-double with 15 points, eight assists and seven rebounds off the bench.