Weird interaction nullision icon

[oli2001]

If has a fyreslayer army i move my banner guy with nullisidian icon , can i try to ignore a spell that has already affected my unit ,since the effect apply in the current phase , my opponent cast a aura spell on a terrain and the effetc is when your within 3 of that terrain you can retreat and  run, i a unit that i want to retreat , so i move my nullsidian banner to place it under the effect of my banner to roll the 4+ to ignore the effect that i can't retreat , is that legal ? 

[Lord Krungharr]

In this case, the Nulsidian Icon would NOT prevent the effects, as the spell was cast onto the terrain, and thus the spell itself is not affecting the Fyreslayers, and they would not be able to retreat.