Undead Warchief Ah, I snuck another lord in there, didnt I
This is the endfor all of you. Sidequest: Catch a Fish Enchantment At the beginning of your upkeep, look at the top card of your library
Currently, that honor goes to the Emblem Foil variant which was only found within 1% of Collector Boosters
I do not consider this as a high power finisher, but more as a solid discard outlet for reanimator/welder strategy, or even a midrange wr deck with nahiri and a bunch of eldrazis as finisher (an archetype that I found out very efficient in the cube, as white is very underdrafted, has the best permanent based hate against unfair decks and red is also often very open as few people are into rdw stratgies)
Many of these dice-rolling cards are creatures that make you roll a die when they enter, when they attack, or when they deal combat damage
On top of that, the tapping also encourages going wide, which Merfolk love to do already with tokens and low cost creatures