Isamaru, Hound of Konda explored the design space of cheap legendary creatures that the new legend rule opened up
You can't exert a creature unless an effect allows you to do so
Note that if it was forked, you cannot win with it, as that won't count as "casting," but something that casts it for free from a non-hand source will count the first time, so something like Golos, Tireless Pilgrim can count as the first time you cast it, and net you seven life and stack it seven down
Blackcleave Goblin Contagious Nim Flensermite Flesh-Eater Imp Glistening Oil Hand of the Praetors Ichor Rats Phyresis Phyrexian Crusader Phyrexian Vatmother Plague Stinger Reaper of Sheoldred Scourge Servant Septic Rats Skithiryx, the Blight Dragon Skithiryx, the Blight Dragon Tainted Strike Toxic Nim Whispering Specter
Psychic Lifetrancer Psychic Lifetrancer was one of the most widely-played synchro monsters of all time when synchros were still relatively new
The combination of rarity, historical significance, and condition scarcity makes it a strong pick for investors looking for the best Yu-Gi-Oh