Riverbank Mistwalkers summon normal Mistwalkers and Etheral Mistwalkers dont.
All three count towards kill 10 part of Needy quest given in Relic and all can drop quest item needed for quest.
All three types like to cast a 1 second stun spell allot and all cast projections. The projection are pets that hit for 700 and have around 4.000 hp they seem to cast projection upon hitting a random health percentage could be at 95% are 10%. Never seen mob cast more then one projection per fight.
Etheral and regular Mistwalkers were not that hard to solo with a 70 necro though my pet seemed to die every fight to projections. Riverbanks I just avoided.
Melee DPS is weak at best. Possibly as weak as a spirit wolf. These two mobs seem to be the weakest in the zone. Their only saving grace is their Spell/Proc, which seems to be recast every thirty seconds if not interupted.
Max Damage done to lvl 70 warrior was 560 as a high, averaged 250ish.
Still farming them for boot spirit mark of water, for boxed cleric.