Inferno is an evil alignmenttown with the demoniac and heretichero classes. Infernos can be found in Erathian regions blighted by the emergence of the underworld on the surface. Demoniac and heretic heroes stand in an uneasy alliance with these towns. Inferno represents Eeofol.
Inferno armies have great hand-to-hand attack units and are only slightly hampered at the lower levels by a lack of flying units until the awesome, teleporting devils can be brought into play.
Castle Gate is a significant advantage of Inferno. It enables to only upgrade creature dwellings in one town, and use the gate to transfer them to be upgraded between towns.
Creating a Demon horde easily: Attack any creep on the map. Blind it, so the battle lasts as long as you want. Cast Fire Wall/Fireball/Inferno/Meteor Shower on your Imps. When they die, raise Demons, then finish the enemy.
Another good thing about the Castle Gate is that one hero can be used to defend all towns.
After the Lich the Magog is the only one with attack in area but is compatible with Frenzy and Bless.
The manual states that Inferno armies have great hand-to-hand attack units, and are slightly hampered at the lower levels by a lack of flying units until the devils arrive. The statement is supported by the fact that compared to their levels, many of the Inferno's creatures have relatively high speed values and maximum damage values. However, lack of flying units is untrue in the sense that Efreeti and Efreet sultans are definitely noteworthy adversaries. While Inferno troops are great for attacking they are not strong defenders which means that combat strategy with Inferno should be based on first strike.
Another weakness in Inferno's army is lack of shooters. Gogs and Magogs are the slowest creatures in Inferno's arsenal, which makes them a somewhat liability considering the mobility of heroes. Additionally, usefulness of Magogs' special ability to throw fireballs is controversial as they may inflict damage to allied troops as well.
Pros
Castle Gate: A life-saver on maps where you control more than one Inferno town.
Pit Lord's Demon summon ability: Lets you horde demons. Consider using Marius whose specialty is Demons as your main hero if using this strategy. If using this strategy, there is almost no need to spend time and resources to upgrade Imps and Gogs or to even build the upgraded buildings since the upgrade does not increase their health.
Efreet Sultans are very good at clearing a map: they have speed, damage, and enough health. They can also be used in a Dragogeddon combo. Consider splitting them into many stacks of 1 unit only in the early game without carrying any other creatures to reduce losses and to increase your hero's movement points.
This town has the highest chance to get the Blind spell in the Mage Guild.
Cerberus are very powerful with Bless/Haste/Counterstrike.
Both Devils/Arch Devils and Cerberi have no enemy retaliation.
The -2 Luck decrease of emenies' Luck is a lot more useful in Horn of the Abyss than without the mod because it introduced negative Luck. Negative Luck gives every stack a chance of 1/12, 1/6, 1/4 with -1, -2, -3 luck to do about half damage only. Assuming the opponent has 7 stacks, on average 0.58/1.17/1.75 stacks will only do about half damage every round if the opponent has -1/-2/-3 luck. This is a significant advantage. Additionally equipped with artifacts that decrease the opponents luck, this can prove to be devastating, especially against wandering creatures who do not have a hero increasing their luck through artifacts.
Cons
If all buildings can be build, Inferno costs the most gold to fully build up. (Castle Gate alone costs 10,000 gold and is not essential; Furthermore, Imps and Gogs upgraded buildings can not be built when using the Demon Farming Strategy).
Arch Devils are very expensive. (But, in hota their ability which decreases enemies' luck got a big boost).
Lacking in the Hero department. (When using Demon Farming, Marius is not terrible at least, and Octavia gives gold for Difficult/Impossible maps).
Imps and Familiars are incredibly weak first level units, and have no redeeming features save their speed (the Familiars' Magic Channel ability is hardly noticeable). (But, they can be sacrificed and raised as Demons).
The Inferno produces the least hit points per week of all the towns. (But it has Demon Farming which partially makes up for it).
Only one ranged unit, and small tier units have low mobility. (Using Demon Farming you will sacrifice those units anyways. Use Marius to get minimum army speed to 7 which is pretty good).
Castle
Rampart
Tower
Inferno
Necropolis
Dungeon
Stronghold
Fortress
Conflux 
Cove 
Factory 
.gif)
Imp 
Familiar 
Gog 
Magog 
Hell Hound 
Cerberus 
Demon 
Horned Demon 
Pit Fiend 
Pit Lord 
Efreeti 
Efreet Sultan 
Devil 
Arch Devil