Hey Spike - the conversion you have listed is illegal - we can only convert cards to pillars or pendulums - nothing else.
The same effect could be achieved by discarding 2 more pends from the deck (hence not discarding the eternity)
Then converting those arsenic into 2 pends.
That said - with our current deck building we are seeing far more pressure on our pillars and pends than on our supply of Eternity.
Yep sry, just saw that i've wrote a bullshit...
Ok then, let's use Snoweb suggestion...
* Salvage: 10 Poison + 2 Arsenic + 4 Discord + 2 Black Hole
* Discard: 2 Eternity + 4 Discord + 12 Pillars + 12 Pends
* Convert:
o 10 Poison => 10 Pends
o 2 Arsenic + 2 Black Hole + 6 Hourglasses => 10 Pillars
* loss: 2 pillars + 2 pendulum + 6 hourglasses + 2 Eternity
* gain : none