Nerds Warding Warden
Arc Warden is powerful lategame core that can be played as position 4-5 support (or offlane utility core) with possibility of transitioning into powerful lategame core. Arc Warden's able to save allies and structures from physical attacks, savely scout with sparks and use items twice (and without spending charges).
This strategy works well against ranged push strats, low mobility heroes. It also works well agains Undying and Phoenix and helps to enable high-damage-low-attack-speed cores while taking objectives. Arc can serve as good push assistaint as well as depusher.
This build is untraditional and situational. Use the hero on this position with this build on your own risk.
Skill Build Timeline
Our main ganking spell. It's not very reliable because it can be muted nearby allies, so you need to get very good moment early to use it: right after new creepwave arrives and when enemy is far away from tower
It's pretty good level 4 nuke, but as level 1 spell it's pretty much only a slow and vision spell. The first thing you do as Arc, is you go to the rune and use a spark wraith on every choke point and rune spawn area. Also use it to harass enemy core from a distance.
Main support spell. Allowes us to save allies from physical attacks and also save structures with a free glyph. Altho, you need to position it in a very good way, so enemy won't be able to bet inside of the field or force enemy to be out of position to get inside. And again, it fully works on tower
Keep TP scroll in your inventory past level 6 and gank with your tempest double, applying pressure and creating kill potential. Double every item, double every spell. With RQQEE combo we can pretty much kill any hero (if you have Q and E on level 4), we can use level 4, double midas, endless charge-based items (drums, diffusal), double hex and so on. You want to get as many active items as you can.
More offensive alternative to force staff. You won't be able to save somebody, but you will be able to initiate from far away with hex or diffusal.
Another reasonable choice: instead of early wind lace or ring of protection you can buy two sets of tangoes.
You won't get much time and space to farm, so most of your money will come from assists and structures, so your midas will be probably late (somewhere between min 16-30), but it's fine: aside from drums and tranquils we don't need that much, while midas will just allow us to buy expensive stuff
Since 6.88 (I believe) pipes stack, so you can get it against high-magic damage lineups (tinker, zeus) and just cover up your team with magic shield twice
It's very expensive for position 4/5 support, but in very long game scenario we will be able to transition into core and we will get a lot of money, so we can afford sheepstick and, well, double hex in fights is very strong.
Some utility to save allies, some mobility, pike upgrade. Pretty nice to have in both agressive and defensive situations: you can save your allies with it, save yourself, reach enemies and, well, you will have not one, but two force staffs.
Another one good pickup. Can be disassebled, can be used on double and original, pretty good choice. Tranquils are usually better because of health regen and armor, which is AW's problems early, but if your team has mana issues, you can pick up arcanes, even as second boot
Gives us a little bit of stats and solves our mana regen issues, so we can spam our spells. And not obly that: you can summon tempest double and use Drum while not spending any charges, basically having endless drums in every fight.
Purging negative effects from allies with doubled speed is quite nice, altho it has low cooldown anyway so somebody else can get it instead
Debuff that prevents multiple healing lasts for almost 38 seconds, greaves have 40 seconds cooldown. It doesn't give us any benefit with double, so you want to get it only when nobody else gets it and your team REALLY needs it
We need to fix some of our mobility issues early. Wind Lace is pretty good for us to have at the start, so we can roam around the map and gank more effectively
Break, -50% damage debuff, all of that can't be dispelled. It provides us invis and some pickoff ability, but think of it more like about utility item: it boosts our stats and damage a little bit, but also gives us ability to turn enemy core into useless hero for a while with this damage reduction