We realize we have spent this entire, sizable, entry talking about one card, but truth be told, it's just that good at illustrating to newcomers what it's like to think outside the box
If your opponent takes out Avacyn, they've got one turn at least to deal with the Shepherd before it brings her right back in a frightful bit of synergy
For example, if you get a trigger from casting a creature spell (e.g., Animar, Soul of ElementsAnimar, Soul of Elements, Beast WhispererBeast Whisperer), you can put that trigger on the stack before Ulaleks trigger, and then pay the two to copy that trigger as well
In naming the format, Wizards of the Coast shied away from Elder Dragon Highlander, largely because of concerns that using the word Highlander might result in legal action, as a result of the fact that it came directly from another intellectual property