All Devouring Wurms

Hi wade . You are clearly a prolific creator!

Broodhunter Wurms
These are a great basic squad for filling up armies (I assume they would have a low point cost). My only remark about them is that every army card in the game has at least 1 ability and at the moment they are left a bit empty. I would suggest giving them something, even if it is not very good. Something like "Whenever a Brodhunter Wurm attacks or blocks a colourless creature roll one extra dice." would provide some kind of action and fit in with the anti-eldrazi theme of Zendikar and the anti-artifact nature of .

Plated Slagwurms
I love the flavour and playability of the burrow / death from below ability. I think, however, the ability would be simplified by making these double faced cards with Plated Slagwurms on the front side and Burrowed Plated Slagwurms on the back side. The wording would then be:
Front side:
BURROW
Instead of moving Plated Slagwurms you may have them become burrowed. If you do, flip this army card.
Back side:
BURROWED
Other figures [unless you want planeswalkers to still be able to get them] cannot have line of sight to Burrowed Plated Slagwurms. Burrowed Plated Slagwurms may move through other figures and ruins [all obstacles are referred to as ruins in the rules]. When counting movement spaces for Burrowed Plated Slagwurms, ignore elevations. [You may or may not want to include a rule about not becoming engaged when burrowed as they will also halt the movement and deal leaving engagement attacks on wandering enemy figures at the moment]
DEATH FROM BELOW
Burrowed Plated Slagwurms can only attack adjacent figures. [see comment below] When a Burrowed Plated Slagwurm attacks a figure, they stop being burrowed. Flip this army card. Until the end of turn, Plated Slagwurms get +1 . [Maybe for the element of surprise?]

With this arrangement of the abilities, it would be clearer to other players whether the Slagwurms were burrowed or not. Any other abilities, such as their hexproof, would need to be printed on both sides, although this leaves it open in case you didn't want something in both states, for example flying.

Also, there was a part of the ability about making an attack on an adjacent figure. The way it is currently worded, if someone could give them a larger range while burrowed, they could attack a non-adjacent figure and stay burrowed so they couldn't be attacked back as there is no line of sight to them. A restriction to only attack adjacent figures could be in the Death from Below ability as above. However, without that first sentence of the ability they will still un-burrow with a non-adjacent attack and the restriction could merely be with a Range of 1 on the burrowed side. This form would also leave design space open for having different Ranges on each side.

Charnelhoard Wurm
UNNAMED ABILITY
Whenever Charnelhoard Wurm attacks and kills and adjacent enemy [this would stop the ability working if an opponent took him and killed one of your creatures with it] squad figure creature you may move a figure from your figure graveyard to your reserve. [makes it sound more like the official cards]

BURROW / DEATH FROM BELOW
Same as above.



Sorry this is a long post (again!) but hope this helps.

Hi wade . I'm glad you appreciate my comments.

Regarding the ability on Charnelhoard Wurm, you are correct, friendly and enemy gets flipped around when being controlled. I was thinking of the interaction of mind control and leaving engagement attacks discussed here in which leaving engagement attacks are optional so the opponent cannot provoke these from your units. As such the Charnelhoard ability needs only to say "...attacks and kills an adjacent enemy squad figure creature, you may...".