Oh I didn't realise you were part of Arcane Wonders! (gulp) In which case I have one question, Dada, please.
I note you made Etherian Lifetree Unique not Legendary to ensure a Druid can always Treebond with it (some match-ups may end up with 2 copies in play double-pumping living weenies on both sides).
If testing has shown Altar of the Iron Guard is not as OP as I feared (I'm very happy to be wrong here, after all it boosts my first love mage), why make it Legendary when Unique would be fairer?
Example: my build relies on Altar (to summon Interceptors guarding ranged, fast cast Bobcat guards or protect spawn point). Why should I be denied playing it for me just because he won initiative so First QC it? I start at a big disadvantage just for losing a coin toss? Ragequit!
If not at least Unique, multiple guard markers could stack (FAQ clarification: remove 1 only per counterstrike, all removed when activated). Although interesting, I assume this is not the intention. I don't see why you have a 4 cost Legendary strategy piece when Unique is fairer.
If it were exactly the same except Unique, it has numerous beneficial effects:
(a) make Spawnpoints better
(b) make Swarm and Zonal Control better (when currently Few Big dominates)
(c) make Warlord slightly better (in school and benefits from both above uses)
My major issue with the promo card was what I wrote in bold capitals in my original post on it in this thread: LEGENDARY ?!?
(Great game, btw! I am converting my local Magic/FFG friends to embrace this intuitive fun game that is so much deeper than it first looks.)