Harsh Sustenance Harsh Sustenance works best in Commander, where players have plenty of time to amass massive board states to blast players away
Start building up your resist either sing for Four Dozen Eggs or get Cogsworth Grandfather Clock into play ASAP to start adding extra defense to your characters
Oskar, Rubbish Reclaimer Oskar, Rubbish Reclaimer uses the graveyard as a temporary stopping ground for cards between discarding them to effects like Jace, Vryn's Prodigy and Likeness Looter and simply casting them to generate some honest card advantage
For the purposes of playing, they are equivalent to one another (that is, you can still only play a maximum of 4 copies in a deck no matter if you are playing the Godzilla Series or Ikoria versions)
You need to take some care and make deliberate choices to maximize this card's potential
Glint-Horn Buccaneer This minotaur pirate is an interesting one, caring specifically about discarding cards