Starter decks was a bit of a misnomer, since these were just like bigger boosters
If you wanted to replicate that Draft experience in Cube form, you'd usually build a Cube consisting of one copy of every rare and mythic, two copies of every uncommon, and three copies of each common from DMU
If Gitrog deals combat damage to a player, which he should, the rider can be sacrificed to draw cards equal to its power
Players or Planeswalkers control powerful spells in the form of a 60-card deck, intent on bringing down the opponent sitting across from them
Due to this, its easy enough to avoid these cards in favor of other options, so its not like theyre must-haves or anything
Its not even legendary, so you can have multiple copies of it