math is not up to date
Parasitic Armor grants 1110 x 3,38 = 3740 bonus armor + 275 = 4015 total armor.
[Ironclad Charge] (1 enemy hit) increases this to 4015 x (1 + (0,5 x 3,38)) = 10780 armor.
Iron Skin has 4044 + (8,5 x 10780) = 94596 base health.

Note that this math is rouded at each step and therefore slightly inaccurate, I didn't want to bother with decimals, the actual result is a bit higher (94856 final Iron Skin health).
Also, since i made this build with Index in mind, i decided to dump range af you really only need one hit on charge to get high numbers
Any augment can be swapped in instead of [Augur Secrets] if prefered. Personally I thing Charge augment is mandatory, but that can also be swapped.

Replace [Fleeting Expertise] with [Primed Flow] outside of the Index