(2018-01-19) If no card is revealed, most likely because that player's library is empty, the exploring creature receives a +1/+1 counter
Core Set 2020 does not feature any new mechanics
Heres every MTG Mirran Sword, when it was first printed, how much it is worth, and its abilities

Cards under $3 that you might consider: Nature's Lore Rishkar's Expertise Cultivate Rampant Growth Farseek Kodama's Reach Colossal Majesty Return of the Wildspeaker Beast Within Nature's Claim Thunderfoot Baloth Rootweaver Druid Reclamation Sage Cathar Commando Knight of Autumn Qasali Pridemage Thrashing Brontodon Ranging Raptors Regisaur Alpha Shifting Ceratops Territorial Hammerskull Territorial Allosaurus Topiary Stomper Atzocan Seer Tribal Forcemage Naya Charm Road of Return Boros Charm Cards that I would call easily expendable: Suncleanser Cacophodon Looming Altisaur Imperial Ceratops Wilderness Reclamation Verdant Haven Gift of Paradise Fertile Ground Oketra's Last Mercy Rolling Thunder Serene Remembrance Elixir of Immortality Oketra's Monument Alhammarret's Archive Sanguine Sacrament Slice in Twain Enter the Unknown Boros Signet Gruul Signet Selesnya Signet lhetrick13 on 3 years ago zigail - Creature cheat is something excels in...casting big stompy creatures for less or for free is a solid plan so your concept is not bad

If a creature card leaves your graveyard, that text box will be lost
These token strategies shine when you switch out the main commander, Inquisitor Greyfax, with the alternate Marneus Calgar