Deck Tech: Glava, Five-Advents Mage
September 8, 2026
Ready for another Bennie deck tech built from the weird new legends from Mystery Booster Commander? X marks the spot with wild Glava nonsense!

Glava, Five-Advents Mage | Art by Zack Stella
We recently got to see all the cool new cards featured in the upcoming Mystery Booster Commander Edition; if you missed seeing them, be sure to read about it here: Mystery Booster Commander Edition Adds 60 Legal Commanders. There are a bunch of new commander designs I'm excited to build decks around, so today I'm bringing you a deck tech built around this wild monogreen creature!
Some Commander content folks will argue a seven-mana creature is too expensive to play in 2026 Commander, but to me some of the most exciting designs are the more expensive designs! Besides, a seven-drop in green is like a four- or five-drop in other colors, so it's all good.
What Does Glava, Five-Advents Mage Do?
Glava's ability can be intuited out by reading the card and thinking it through, but for clarity's sake I'm porting over some of the explanations laid out in the Mystery Booster Commander Release Notes:
- Suppose you control Glava and cast Endless One, a creature spell with mana cost and "This creature enters with X +1/+1 counters on it." You can choose 0 as the value of X as you cast the spell, pay to cast it, and the mana value of that spell is 0 immediately after you cast it. Glava's ability triggers. When the ability resolves, you can choose to have the value of X become 5. If you do, the mana value of Endless One on the stack becomes 5, and Endless One will enter with five +1/+1 counters on it.
- Spells with additional costs that include won't be affected by Glava's ability. must be in the spell's mana cost.
- An ability with a cost that includes X, but not the mana symbol , won't be affected.
- Activated abilities contain a colon. They're generally written "[Cost]: [Effect]." Some keyword abilities are activated abilities and will have a colon in their reminder text. Triggered abilities (starting with "when," "whenever," or "at") that ask a player to pay aren't affected.
- Glava's ability doesn't change the amount of mana you have to pay.
So basically, once each turn when you cast a permanent spell with in its mana cost, or an ability with in its activation cost, you get to replace the with . If you time it right, you'll actually get to double spell or get that activation on the same turn as you play Glava, and it's excellent to get value from your seven-mana spell right away. This deck will be a big mana deck with lots of upper cost mana ramp, along with cards that let you play multiple lands per turn.
Key Cards for Glava, Five-Advents Mage
The first cards I looked for were creatures with the ravenous mechanic, which is perfect for this deck. These are all creatures with in the mana cost, and the ravenous mechanic says if X is 5 or more you get to draw a card, so you'll definitely want to hang onto at least one of these for the turn you play Glava so you can get that X = 5 and draw a card to keep the fuel going.
Aberrant provides some reusable ways to destroy artifacts and enchantments if you trample through and deal combat damage to a player. Tervigon can hopefully churn out some 1/1 Tyranid token creatures to act as chump blockers, and Tyrant Guard gives us some measure of protection for creatures with counters on them.
Termagant Swarm and Hormagaunt Horde provide some resistance to mass removal, while Broodlord is a way to distribute more +1/+1 counters to other creatures, and at least a few should buff up Glava.
Sporocyst has that double in the mana cost, and it would be incredibly nice to cast this the same turn as you've played Glava so you can ramp your lands by five. Kinetic Ooze has a lot going on, but one of them is basically the ravenous mechanic where if X is 5 or greater you get to draw a card.
I went looking for other permanent spells with X in the casting cost, and there are some sweet Hydra creatures to choose from. Goldvein Hydra comes down and gets attacking right away, and it provides Treasures when it dies. Lifeblood Hydra provides extra cards when it dies, and Hungering Hydra grows if it's dealt damage and survives.
Rampaging Yao Guai always felt a little expensive for what it did, but if you can cast X for five without that extra mana investment thanks to Glava, it seems worth a slot for its artifact and enchantment cleanup capability. Lattice Library seems like a nifty way to generate some extra token creatures each time you cast a spell with in the mana cost. I've not seen it in action yet, so if you have played it or played against it let me know what you thought of it!
I'm really excited to play spells with in their cost and assign five for X with Glava! Marketback Walker and Walking Ballista are classics, and I can't wait to throw five d6s for Neverwinter Hydra!
Mana Bloom is a wild card in this deck: cast it early to ramp out Glava, and have a mana available on opponents' turns; later, when it returns to your hand, you can cast it with Glava to get five charge counters on it. Astral Cornucopia has that triple in the casting cost, so casting it the turn you cast Glava is going to be huge game! Gwenna, Eyes of Gaea is a great card to set up casting Glava, untapping Gwenna and then have two more mana to cast on of your X creatures.
With all the X spells, I've included some cards that support the theme. Nexos is awesome for playing some of those X spells before you have Glava out there. Unbound Flourishing and Branching Evolution have similar functions, mostly doubling the +1/+1 counters you put on your X creatures.
Magus of the Candelabra is a great card to have out the turn you cast Glava, since you can use Glava's ability to untap X lands, where X equals five. Glava allows you to use the channel ability of Shigeki, Jukai Visionary to return five nonlegendary cards from your graveyard to your hand. Green always has issues with fliers, so Silklash Spider is there to keep the skies clean.
Polukranos, World Eater and Hydra Broodmaster have fun monstrous abilities with in the cost that are going to be fun to pay at the Glava discount.
The big limiter of Glava's power is that it's capped at once per turn... so why not ensure you can cast X creatures on your opponents' turns? Radagast of Rhosgobel is a new, juiced-up version of Yeva, Nature's Herald, but both serve this role quite well. Savage Summoning is a nice one-shot way to do this that will even give an extra +1/+1 counter for your troubles.
Runadi, Behemoth Caller is a spicy card for this deck, tapping for mana and often throwing around some extra +1/+1 counters on your larger mana creatures. Chances are pretty good that you'll have creatures with total power of ten or greater to activate Mosswort Bridge.
As a green deck with tons of mana sinks and an expensive commander, it's not surprising that I'm running a ton of mana acceleration, and I wanted to call out of few of them here.
It's incredibly easy to unlock the ferocious ability of Fanatic of Rhonas in this deck, allowing it to generate a whopping ! And then there's the new hotness The Notary Hobbits which is hard to stop outside of a battlefield sweeper, and all these ravenous creatures are an excellent candidate for all the colorless mana these Halflings can generate.
Between running 39 lands, a bunch of MDFCs cards that can also be played as lands, and a good amount of card draw, cards like Gaea's Touch, Loot, Exuberant Explorer, and Case of the Locked Hothouse letting you play an extra land each turn is going to get a ton of mileage.
And since I'm running both Arid Archway and Guildless Commons, getting to play those extra lands really unlock the power of these cards.
Goreclaw, Terror of Qal Sisma is mostly here to help cast Glava, but leading an attack and giving your large team trample is going to help push through a lot of damage Throne of Eldraine is solid mana ramp to cast a seven mana commander, and is also an excellent mana sink to draw cards if you're looking for gas.
How Does This Glava, Five-Advents Mage Commander Deck Win?
This deck is going to win through combat and crashing into life totals with huge (hopefully trampling) Hydras and other monsters.
Kinetic Ooze will often present an "oops, I win now" opportunity in the later game where you have access to eleven mana and pump ten or more mana into its X cost, which unlocks all three of its abilities: destroy an artifact or enchantment, draw a card, and then double the number of +1/+1 counters on any number of other creatures. Boom!
Glava, Five-Advents Mage Commander Deck List
Conclusion
As usual, I built this deck to roam firmly in the Core (Bracket 2) pods out there. If you like long, grindy games with plenty of big haymakers to wind up the game, this deck might be one worth checking out.
Which other cards would you add to your Glava deck? What other legendary creatures from Mystery Booster Commander do you find cool and interesting?
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