(edited by Raksha.8049)
iWarden issues?
Are you summoning the iwarden first before you do anything else? The only time I have had issues with it being insta gibbed is if I start off a rotation with it, monsters tend to realize it is there before it renders on the screen. I will assume if you are using s/f you are probably running some variant of a power build, either focusing on phantasms (from the sound of it) or shatters. Which chances are you are not running very much toughness, toughness goes a long way to making the phantasms and clones sturdier. The trait that gives extra hp to the phantasms currently is not working optimally as it applies the bonus health on a small delay. Either way even with a ton of toughness and boosting traits for phantasm sturdiness they will rarely survive more than two hits at best.