Another new entry for the Cults compared to yesteryear, the Acolyte Iconward is a prime specimen of genestealer infection in an early generation. In his hands / claws / appendages is the icon of the cult -- a kind of inspiring sacred relic somewhere between religious icon and military banner.
The Iconward has a slightly better statistic line compared to the ordinary hybrid (most obviously the extra wound). However, it is the presence of the banner that marks the Iconward out. The banner provides a large bubble of furious charge that the cult can take advantage of. In addition, he also provides a much needed bubble of feel no pain that at least can give a layer of protection to the otherwise rather poor 5+ saves that the army mostly has.
Beyond these most obvious boons, the Iconward is not much to look at overall.
The only optional extra here is to take something from the relics list. I'm not sure its worth the investment overall to be honest. Hence my thought here is to just keep it simple and go with the basic build to save some points.