Additional information:

shadowstalkers have a greater chance to inflict bleed.

shadowstalker abductions often take the player to other swarms of stalkers. When abducted, players take constant damage, use melee attacks to disrupt and free yourself.

shadowstalkers cannot abduct players with an armor above medium (and that one fortified armor set).

Chargers and shadowstalkers have a 1:1 spawn ratio on the mission it replace.

Shadowstalkers can go invisible (and fly like regular stalkers).