Grrrr. Still waiting for Eelektross. I'm just going to keep waiting.
Anyway, Darmanitan. Gotta love that monster attack stat.
Choicemanitan
Ability: Sheer Force
Nature: Jolly/Adamant
EVs: 252 ATK and Speed, 4 HP
@: Choice Scarf/Choice Band
-Flare Blitz/Fire Punch
-Superpower
-Rock Slide
-Earthquake
Darmanitan's stats put it in the direction of a choice item user. Two 120 power attacks and two 100 power attacks. Awesome. Fire Punch can be used over Flare Blitz if you have an issue with the recoil.
Bulkmanitan
Ability: Sheer Force
Nature: Jolly
EVs: same as the last one
@: Life Orb/Leftovers
-Bulk Up
-Flare Blitz/Fire Punch
-Earthquake
-Rock Slide
Not too difficult to figure out.
Drummanitan
Ability: Sheer Force
Nature: Jolly
EVs: same as the last one
@: Life Orb/Leftovers/Salac Berry
-Belly Drum
-Fire Punch
-Earthquake|Substitute
-Rock Slide|Focus Punch
This can be a straightforward Belly Drum route, or a variation of Bellyzard. Either way, you need great prediction.
Chargemanitan
Ability: Sheer Force
Nature: Adamant
EVs: same as the last one
@: Life Orb/Leftovers
-Flame Charge
-Flare Blitz/Fire Punch/Rock Slide/Earthquake/Superpower
-Flare Blitz/Fire Punch/Rock Slide/Earthquake/Superpower
-Flare Blitz/Fire Punch/Rock Slide/Earthquake/Superpower
Perhaps this should be known as "Rocketmanitan"! Flame Charge will kick some speed and then you launch some monster power.
Zenmanitan-Doll Style!
Ability: Zen Mode
Nature: Modest
EVs: 252 Special Attack/126 defense and special defense/4 HP
@: Wise Glasses/Black Sludge/Petaya Berry
-Substitute
-Flamethrower/Fire Blast/Overheat
-Psychic
-Focus Blast/Grass Knot
The idea is to trigger Zen Mode manually. Substitute cuts the HP to activate the Zen. After that, special attacks. Black Sludge is an option, but a very dangerous one. It quickens the activation of Zen Mode, but it also limits how long this can be used. If you want to be safe, give it Wise Glasses. Since Zenmanitan will be with low HP, Petaya Berry can work great.
Zenmanitan-Choice style!
Ability: Zen Mode
Nature: Modest
EVs: 252 Defense and Special Defense/4 Special Attack
@: Choice Specs
-Flamethrower/Overheat/Fire Blast
-Grass Knot
-Psychic
-Focus Blast
Let your opponent unleash Darmanitan's Zen by taking damage. The EVs may seem odd, but Pre-Zen Mode Darmanitan is fragile, so it needs the bulk to survive.
Counters
Aerodactyle can one-hit it with Stone Edge. It can switch into the fire attack and Earthquake and Darmanitan down. Also, Stealth Rock will not be something that Darmanitan will appreciate, unless it has Zen Mode. Basically, a solid super effective attack from something faster will put it down. Otherwise, Gyarados can switch into anything not called Stone Edge and trigger Intimidate and smash through with Waterfall. The traditional Physical Walls like Skarmory and Forretress are benched here for obvious reasons.
As for Zenmanitan, Chansey, Gyarados, and to a lesser extent Snorlax can tolerate Zenmanitan and cripple the lowered HP with Toxic.
Cinccino will get a special mention because of Skill Link Rock Blast. It breaks Substitutes and the squishy Darmanitan it shields. However, Zenmanitan may have enough bulk when Zen Mode is active. Another way to counter Zenmanitan is the move Heal Pulse.
Other Options
Physical STAB on Zenmanitan can work as something to use while you are not in Zen Mode, but it's better to just try to activate it.
Belly Drum can automatically activate Zen Mode, but the better route is to use substitute because it's safer.
Hammer Arm can be used over Superpower if the attack drop is something you want to avoid, but Darmanitan will still have plenty of attack after a Superpower and a drop in speed and base power and accuracy is a worse way to go.
Brick Break is a choice if you don't want any stat drops.
Uproar is a special mention because it makes Darmanitan immune to sleep, but Darmanitan does not want to be locked at all, Zen Mode or not.
Focus Sash can be useful for activating Zen Mode, but the slow down factor and the common sandstorms make you look bad. It could work with a non-Zen Darmanitan for a lead set with Taunt and U-Turn, but that is something that puts Darmanitan's offensive magic through waste management plants. Better to think "how can I sweep the unlucky soul?" rather than "how can I annoy the unlucky soul?" when using Darmanitan.
Speaking of which, U-Turn can be useful for hit and run tactics. But passing up an uber-power move (100+ base power) for guerrilla tactics pacifies that 140 attack stat.
Stone Edge gets critical hits, but don't depend on criticals. Ever. You can rely on them, but not depend on them. Besides, Rock Slide hits harder, which I unfortunately found out significantly later.
Salac Berry can be used with outside of Drummanitan, but its not a good idea. Same goes for Liechi Berry.
I hope I did well. Please comment, I want some feedback on how well I'm doing!