I could make a bunch of detailed suggestions, but instead I'll just post my Glissa list. It's gone through a bunch of editing, and ever card is in there for a reason. Hope it helps.

http://tappedout.net/mtg-decks/glissa-ehd/

So why is thornbite staff in the deck?

Thornbite Staff turns any creature with deathtouch into a machine gun. Glissa, the Traitor pings a creature for 2 mana, and I recur an an artifact from my graveyard.

I think you should either add more artifact bump, more ramp, more lands, or cut down on your cmc. I think cutting back on the higher cmc would be the most effective. But doing a bit of everything would be the best.

Kusari-Gama + deathtouch creature = opponent creature board wipe ;)

misread, the equipment does the second half of damage but may still be good for your deck.

due to the equipment still hitting all of the defending players creatures.

Idk if you want but thrown in Undying Evil with Triskelion you win.

Rune-Scarred Demon is a good one too. If you got the trades Survival of the Fittest . I would also put a Greater Good helps when people are trying to board wipe or take control of a big creature you have.

samj, that doesnt work. it re-enters as a different object.

What doesn't work? Nothing I said "doesn't work," it all works... If Triskelion has undying its an infinit loop look it up.

Yeah it your right with Mikaeus, the Unhallowed it work because of the static ability it has... Why would the ability of the creature fizzle though if the ability takes hold when it's out of play? Would it not just keep happening until the turn was over? That's a weird ruling because the creature is technically out of play when it hits the grave yard.

It's because the creature hits the graveyard and then undying triggers, and then the original creature re-enters as a different object. If it would dye again, it wouldn't have undying since the Undying Evil targeted the original object not the new one. Mikaeus's ability makes all creatures have the ability, but undying evil is a single use per the originally targeted object.

Also just another note for the deck designer. Spellskite has blue in it's color identity so it can't be used in a glissa deck. Just worth noting since it is in your maybe board.

AzrielBarakiel I thought color identity just referred to the casting cost? Any activated ability costs are not counted as color identity. I think Spellskite is legal because his color identity is "colorless," but I'll double check.

Incorrect, for example, Memnarch can be used as a mono blue commander. Color identity is any color marker on the card, excluding reminder text which is not technically part of the card.

Greetings from Glissa, the Traitor: The Incredible Machine. Here's a few comments from my end:

Not sure I would play both Oblivion Stone and That Which Was Taken . I know they're not exactly the same, but they occupy a similar space and are both somewhat mana-intensive.

Massacre Wurm was one of my favourite cards while it was in standard, but I have personally found it underwhelming in EDH. I can see this being a meta choice though, maybe you have a tokens player in your group?

Not enough swamps for Cabal Coffers , even with the Urborg. I say get some more dual sources in here, even the ones that come in tapped are worth it: Golgari Guildgate etc...

Got a +1 from me, look forward to seeing future versions.

Cabal Coffers is great in this deck, I can fetch it alongside Urborg, Tomb of Yawgmoth with a recurred Expedition Map . And yes, I play two token decks in my group, Rhys the Redeemed and a Krenko, Mob Boss .

2 bows and 2 whips? Whooopsie.

scratch that... you must have changed when my comment was sent.

Keep whip in. The Lifelink in black is too good to not have.

@Dorotheus, yeah I noticed that as soon as I hit "deckcycle." I didn't mean to remove the whip, as I was trying to find room for Reaper from the Abyss . He likes sharing a field with Sheoldred and Glissa.

Reaper from the Abyss might kill Glissa though :(

you're right, I also just learned about Lurking Predators , I had to put that in.