I like the summoning, because with the BW and the COGS, I summon an Engine turn 2, and for a 1k list, it's a huge impact. So, in these games, I use my skinks, either the 10 block or the 30 block (it depends of the game) to protect my slann. And while my opponent, was occupied at charging my skinks but not fighting them (thanks wary fighter ), my slann stack up some conjuration points and turn 2, baam ! An engine ! During that time, my ripper take out some key units and even survive well.