Think Angel of the Ruins, Krosan Tusker, Striped Riverwinder, and Shefet Monitor
I do invest some money into Arena for cards and events, but I too do not have a playset of every relevant card on Arena (although a spreadsheet that teaches you how to draft to facilitate collecting has been a big help to me as of late
X TRAP (This card is always treated as a "Rescue-ACE" card.) If you control a "Rescue-ACE" monster: Target 1 Effect Monster your opponent controls
Unlike Kiteroid and the remaining Spells, I think Monster Reborn is a staple in this build because all the Level 4s (besides Box) have an on-summon effect & you can use it to bring back Howitzer.
But Xyris wants to throw reservations out for a much more unbound and fast-paced deck
He was literally the biggest, scariest creature in the game in 1993, and with both Animate Dead and Dark Ritual in the first set, he could hit the battlefield well before turn seven, so he was a very in-demand card