If Rundvelt Hordemaster and one or more other Goblins you control die at the same time, its ability will trigger once for each of them
Mew ex (151/165) has spiked 30% to $100-120, driven by its elusive design and meta relevance
Before long though, we can see HP values of 400 being breached, rising in parallel to attacks, which are also increasing in strength, thanks to the constant demand for more powerful and impressive cards
Generally speaking, though, I don't think that any one is more important than the other two
Swarmyard Until its appearance in Bloomburrow Commander, your art options for Swarmyard were pretty extreme
There are also Stadium cards that provide an effect for both sides, but only one Stadium can be in play at a time, so players will engage in whats called a Stadium war where they fight to override the opponents Stadium and keep theirs active