This is all still a bit speculative on my part - I think I've figured out a good way to play Asphodel but haven't yet tested it in a multiplayer setting. I'll probably be amending this quite a bit in the future. -Sopbucket

Ideally you'll take an awake pretender to help with expansion - good choices are the Carrion Dragon (with Reforming Flesh and an Earth path) or the Drakon. Because you're a pop kill nation, you'll want to tank order, production, and heat scales since these don't matter as much over the course of the game. You should max out Growth and Magic for better freespawn, and put as much as you can into Luck for extra gold and gems.

An awake expander helps you secure forests in the expansion phase, protects you against early assaults, and gives you the ability to grow fortresses and cast Mother Oak without having to rely on Panic Apostates and boosters, jumpstarting your economy early on.

On turn 1, recruit a Panic Apostate and three Centauride Warriors. Set your Carrion Centaur to reanimate and move the Satyrs to your Minotaur Lord. Make Alteration 5 your research target and research with your pretender, or expand blindly if you dare.

In the next few turns, use your Panic Apostate to site search and focus on recruiting Black Dryads for research. You can recruit Black Harpy scouts and Minotaur Lord commanders in the forest provinces you take. Continue recruiting Centaur/Centauride Warriors and expand in parties of 9 to 11; be sure Minotaur Lords are set to Stay Behind Troops or they will be killed. Try to move your expansion toward forest clusters if you can.

Don't spend your nature gems, and prepare to cast Grow Fortress on turn 6 with your pretender. This requires you to first build a lab in a forest province, which you will want to follow up with a temple. Continue recruiting Black Dryads at your new fort as well, until you get close to Alteration 5. By turn 17, you should be able to cast Mother Oak using your pretender - this is a good reason to take Nature 5 at your pretender creation. Alternatively, you can research Construction 4 and make a thistle mace to put on a Nature random Panic Apostate; this should allow you to cast Mother Oak around turn 21 which is still quite early. This way, you should be able to claim the global before anyone else does, and the extra nature gems will be crucial for building forts and reanimators more quickly, helping you snowball in strength.

Once you have Alteration 5, a good new target is Enchantment 5, as this gives you Twiceborn, Foul Vapors, Horde of Skeletons, Dark Slumber, and Faery Trod. Grab Construction 4 for thug gear if you don't have it, then continue on to Alteration 6.

Do NOT use your freespawn to expand - without large numbers and spell support they will just die in droves. After casting Mother Oak, summon a Carrion Lord and prophetize it, then gather all your freespawn into one army under this commander and a few supporting Panic Apostates. Carrion Growth combined with Wooden Warriors will make this force quite effective and cut down on attrition a lot.

With the rest of your nature gems, focus on summoning Bramble Forts and Carrion Centaurs, which are your most efficient reanimators per gem use. Bramble Forts do not increase your freespawn, but you'll need them to recruit more Dryads and Apostates, and to protect your temples.

After the expansion phase, you'll want to focus on recruiting mages over troops for as long as you can get away with it. This focus allows a well functioning Asphodel (with four or five forts) to surge in research in the mid game, making them quite formidable at this stage. It may be a good idea at this point to go after lands that you plan to keep out of your domininion, as you will need a tax base to support your growing mage army. At some point increasing upkeep combined with falling income will force you to stop recruiting researchers in all of your forts, every turn.

Good research targets at this point are Conjuration 6 for Lamia Queens, Howl, and Strength of Gaia, Enchantment 6 for Rigor Mortis, Alteration 7 for Mass Protection, Creeping Doom, Army of Giants, Darkness, and Soul Vortex, and Thaumaturgy 6 for Syllable of Sleep.

You'll want to make use of twiceborn transformed Dryads and Apostates - the former give you additional reanimators, created with Death gems instead of Nature, and the latter give you tough thugs/SCs. Battles at this stage will consist of either concentrated freespawn armies, or kitted thugs. Groups of Apostates can raid effectively using Horde of Skeletons, and so twiceborn enchanted Apostates don't need to be killed off immediately. You can have Black Dryads cast Twiceborn on themselves by giving them a Skull Staff.

The best Apostate thugs are the Death and Earth randoms. These can both raise their base protection through spells, and Death randoms can additionally use Soul Vortex, absorbing health and fatigue from those around them. You can equip these thugs with a Frost Brand, Vine Shield, and Kithaironic Lion Pelt, and they will perform just fine against most groups of enemies, just 20 gems or 14 with Dwarven Hammers. Keep in mind the twiceborn Carrion Lord form is also a manikin and sacred, so a dryad accompanying a thug can be scripted to cast Regrowth, Bless, and then retreat, giving it a blessing and regeneration. A Reforming Flesh bless stacks with this regeneration, totaling 20% regen per round.

Water random Apostates are still valuable for being able to cast Foul Vapors, a great way to kill enemy mages. Nature randoms are probably best tasked with casting supporting nature spells in large armies, Earth randoms are similarly good at this role because they can cast Strength of Gaia to boost Nature in combat.

You can use dryads to preach in enemy lands, spreading your awful scales and pop killing dominion there. This could be a way to fight back against a superior foe that you can't face directly.

I doubt Asphodel has a particularly strong late game, other nations will start to catch up and then surpass them in research, hard counters against undead start to show up, troops will be less effective overall and the corpses needed to generate manikins will start to go away. That said their magic should still be fairly useful.

After Alteration 7, it might be best to continue down Conjuration. Well of Misery, Wild Growth, Faery Court, and eventually Tartarians, assuming you have high death paths on your pretender. This could open you up to more magic diversity. A number of immortal summons are open to you; worm mages, liches, wraith lords. All of your thugs can cast Charm. Storm of Thorns and Disintegrate.