If that creature is still on the battlefield when the ability resolves, it'll be counted if appropriate.
Garland, Royal Kidnapper Garrulous Sycophant Grave Venerations Heart-Shaped Herb Jared Carthalion, True Heir Kavu Monarch Keeper of Keys King Solomon's Frogs Knights of the Black Rose M'Baku, Jabari Chieftain Marchesa's Decree Marchesa, Resolute Monarch Nakia, Wakandan Operative Naturalize 2 (playtest) Oath of Eorl Okoye, Mighty and Adored Palace Jailer Palace Sentinels Paliano Protector of the Crown Queen Marchesa Queen Mother Ramonda Regal Behemoth Regal Sliver Skyline Despot Squee, Dubious Monarch Starscream, Power Hungry Starscream, Seeker Leader Staunch Throneguard T'Chaka, Venerable King The Spear of Bashenga Thorn of the Black Rose Throne Warden Throne of the High City Wowzer, the Aspirational (playtest) omer, King of Rohan
You can have as many Cids in your deck as you like, but only one on the battlefield at a time - as he is a legendary creature
By ramping into big creatures, you set up a continuous source of mana and card draw over time
For information on 2025 releases, ICv2's Pokemon TCG 2025 release calendar (see "'Pokemon TCG' 2025")