Lightwardens are aether, hence the cs of the aether flowing into you. White auracite could be contained long enough to teleport to the Crystal Tower, especially after Ryne was able to stabilize our aether after taking in the light. Don't need it to kill the Warden, Thancred could have done that with Ryne and the others due to Innocence being the only 8 man Lightwarden and only after Vauthry suffused himself with light after gorging himself on meol. Hell, Ryne was also capable of containing the light, but was only to be used as a last ditch effort if we couldn't be summoned on time.
Sorry man.
It's a vacuum, right? So the entity that kills the Warden HAS to be the host? I thought it only had to be the close enough person/creature, because that is what is said by the Exarch after Philia. So it wouldn't necessarily seek out the archer a quarter mile away that landed the lucky shot, but the warrior out in front next to the thing, right? So if the auracite is closer to the warden, the aether vacuum would take it first before it went anywhere else?