Elhain is fine to max in my opinion. Her usefullness dies off later on, but you gotta play someone those fist 60-90 days and she's ideal unless you get some random fantastic shard pull.
Eating HK was a mistake though.
MM at 60 with Scyl should be able to keep Suzerain, elhain, and someone else alive long enough to do some serious work in dungeons. Gear makes all the difference, don't underestimate accuracy, and lots of champs benefit massively from 100% crit rate. Focus on those stats. Your scyl has enough accuracy for level 10 dungeons, need to get them all above 200 for the level 20 dungeons.