The other two options arent bad, but Mirri, Weatherlight Duelist strikes me as more of a support piece than a legendary creature to build around
Something like Xyris, the Writhing Storm or Nekusar, the Mindrazer needs its commanders to survive to win the game
Since its a cast trigger, that spell doesnt have to resolve to get the energy, but that means you cant get it from other artifacts just entering the battlefield
The Icelandic Sensation (I'm so close to calling her Bjork) is on-color and will do the same recursion that Body Double does
This just goes to show that Deathspeaker lists can find a home in various strategies
Ideally, at this point, you should be revealing lands in order to make Insect tokens off of Springheart Nantuko while searching for a Bristly Bill to start putting +1/+1 counters on Nadu or other potential attackers