Use a Conjurer's Closet, Ephemerate, or just about any other flicker spell to keep Yojimbo from triggering that final stage, and you've got a rather gnarly 5/5 and other, oppressive effects all in a single package
Thunder Magic Rating: 4/10 The split card between 2 damage for 1 mana or 4 damage for 4 mana is pretty strong
That being said it does have some downsides as some cards can really punish you for using abilities, drawing or discarding
Pushing the impactful cards to higher rarities helps make the games more even-keeled in Limited because of card as-fans (the rate at which a certain card or subset of cards show up within an average booster pack) and in casual Constructed because of card availability
Rather, a second "reflexive" ability triggers when you create an Assassin token this way
Itll be weaker than Crucible in some respects, because it will be more vulnerable to removal as a creature