This is a pretty straightforward build for survivability, soloing and, most important, Index. Exilus mod is not needed, but as always can help.
You don't need so many formas, for example, [Corrosive Projection] is not needed if you can get [Steel Charge]. So if you can live with this change, you will only need a forma, not more. It is to be said however, that CP helps the whole team, so it's always welcome.

If you can't get yourself corrupted mods, you want however, to increase the strength to the highest possible point. Don't mind duration, or range. You are using this build to get the highest amount of armor possible and be virtually unkillable.

This build, aiming for the highest possible strength, is specially indicated for people who just started playing and need to stay alive in missions more than anything.

You can use stomp ([Rhino]'s 4th) to knock down everything around you, hurt them and give you the time to recast Iron skin or to escape from a nasty situation.