Help understanding mechanic?

Hello guys. I’m a semi-new player to MTG: Arena. Today I had a match vs. an opponent with 2 Roaming Thrones in the board. I used a Fell (cost 2 mana) and paid the 2 mana “fee” to break the ward on one of their Roaming Thrones but it didn’t destroy the creature :/ The Roaming Throne was deemed “cleric” and so was their second Throne. No other creatures were on the board for them. Can someone please explain why my Fell didn’t destroy their Roaming Thrones, despite paying the 2 mana ward fee? Thanks!

Hello guys. I’m a semi-new player to MTG: Arena. Today I had a match vs. an opponent with 2 Roaming Thrones in the board. I used a Fell (cost 2 mana) and paid the 2 mana “fee” to break the ward on one of their Roaming Thrones but it didn’t destroy the creature :/ The Roaming Throne was deemed “cleric” and so was their second Throne. No other creatures were on the board for them. Can someone please explain why my Fell didn’t destroy their Roaming Thrones, despite paying the 2 mana ward fee? Thanks!