Horned Turtle is a really nice defensive card, especially when its also a looter
As a standard, they all have some kind of main theme , and several sub-themes , which usually means the gameplay isn't always consistent
As for a deck I'd suggest you add this little Alien to, lets pair it up with Niv-Mizzet, ParunNiv-Mizzet, Parun
You might have interactions with the top of your library like surveil, Terminus, or Selvala, Explorer Returned so you want to stack it precisely
Instead, look for build-around cards like Dread Presence, Empyrean Eagle, Gnarlback Rhino, or cards with traits you know you'll use like removal and cheap ramp (examples: Chandra's Outrage, or Leafkin Druid)
Zarude V: With the silvery foil line, this new Mythical Pokmon looks like a force to be reckoned with