Hi all,
I will try to explain my build with sedna, is easy to play, cheap to max and a lot of fun to play.
General strategy
Your objective is to be the fastest DG of the playground, so u will be able to chase everyone, run when needed and be quickly in every place of the map that u need without endless teleports, maximizing this build is easy and very cheap so u are going to play a full support role, not only helping and healing friends, u will get most of the fortress upgrades becouse thats where the most of your money will go.
A lot of guides are about how to maximize the DG power, items and stuff, with this build this is secondary, lets see it.
The build
Heal I
Inner Grace I
Pounce I
Heal II
Pounce II
Inner Grace II
Heal III
Pounce III
Inner grace III
Pounce IV
Heal IV
Silence I
Healing Wind I
Healing Wind II
Counter Healing
What ever u need...
Items
Favor item: Swift anklet
Starting items: Banded armour, scalemail
Buyed items: Scaled helm, Vlemish faceward, Plenor battlecrown, wand of speed.
This is all that u are going to need until the end of the game, in a normal game u are going to get it in middlegame.
Getting items is not the first mandatory stuff to do, it depends of the game and enemies, u usually will mix them with buying fortress upgrades, like tower regen, improved gold(this must be asap) and creeps mostly.
Early game
Your job is to get all the flags u can and try to keep them as long as possible, dont start dogfighting if u are not completely sure u are going to win, the best thing u can do is hit and run, u will deplete the HP and mana pool of the enemies and u will force them to go back to base, at this point u dont will have a lot of mana so just play to make them go back to base and keep the lane, try to never go back to base, if u are being hitted hard just move to other zone to get another flag, to be up in warscore is your main weapon and objective.
Mid game
U should have all the items mentioned above plus the gold improvement of the base, at this point u have all that u really need so u can focus on fortress improvements, this must be your main focus, when u go up a warlevel buy asap the new thing that u need, creeps, trebuchets, whatever, u allways must have money waiting to buy the next needed upgrade asap, u can buy lvl 4 priests when u can too but this is just if u have enought money for the upgrades.
At this point u are going to be the fastest DG in game hands down, the wand of speed is your friend, use it all the time, to go to base, to chase enemies, to run, allways must be with the cold down on.
Dont worry if the enemy demigods have pushed a couple of towers, while u are up in warscore this will change fast.
Get flags, get flags and... get flags, fight when needed or to defend the flags but never do mindless combats while u dont have map control, if u must fight do it for something.
Late game
Buy locks and ninjacap portals, enemy portals are your priority, with ur speed u are going to be a nightmare for the enemy capping places, no one will follow u, u allways will have this advantage upon them so use it.
If u have a ton of money u can get an artifact, i usually get bulwark of the ages so i can go wherever i want without problems, at this point u are an inmortal lightningh 
General notes
Try to buy a couple of mana potions, they are worth it, if u run out of mana, use it and go back to fight, flag lockers are your friends too
.
At the end, u will have 3 early game items, if u see that u need more, mana, speed, hp or whatever, u have 3 slots to replace whatever u want, just be sure that u have money for fortress upgrades as stated before
.
At the end of the game u usually will finish without deads(or a few) and a couple/ton
of kills, the enemies will fear u, not becouse your dps but becouse they will know soon that there is no escape if they fail or wait too munch in front of u, psychology is very inportant
.
When a unclean beast dies chased by u and cant kill u becouse u run more, the fear will surround him, this is one of the funniest parts of this build 
Have fun¡¡¡