No need to keep Legolas alive. Play him, kill a minion, and let him die.
Gamling's text allows you to play possessions during the skirmish phase on him.
Heavy Chain, or even
Armor, can be nice on Eomer.
There are better builds, but for what you are going for here (just drop possessions to cycle), it should be okay.
I didn't really look at the Shadow, but that is a ton of high cost minions...
-wtk