>>531677147
Intensify is the best umbral mod, to the point people will run it on non umbral frames if they have the room. The other two are used exclusively for health tanks (memes), so I wouldn't push either past r5 unless you want to bling out your inaros or something.
Excal umbra is pretty strong, but this augment is mandatory. Otherwise umbra runs around on his own and all kinds of retarded shit that will screw you over happens.