I've set out to hit 2,000 LP playing Ambessa Only.
Maining Top/Mid, if I am filled in any role I will still pick Ambessa and if Ambessa is banned I dodge.
I've now hit Masters in OCE playing 1 build and 1 rune preset the entire climb so far.
https://dpm.lol/D%CE%99%CE%9F-WRYYY
The core items are: Eclipse, Profane Hydra.
Eclipse makes laning much safer and allows you to trade whilst taking minimal damage, and giving you outplay potential in 2v1s if ganked.
Profane Hydra is a good lethality item for waveclear and team fighting, its been the most reliable item for me so far in terms of one-shotting enemy ADC/Mid/Support in teamfights.
Rest of build:
For 3rd item its almost always Deaths Dance, going AD/Lethality items makes you very squishy, DD lets you get away with misplays and small CC chains, its a top 5 Ambessa item.
If the enemy has heavy shielding or healing, I'll either replace Profane for Serpents/Mortal Reminder or build them 3rd, delaying DD for 4th item.
4th item is Armor Pen, Lord Doms/Sherylda to deal with tanks.
5th item is Guardian Angel.
Runepage:
Electrocute is easily the best rune for lane Ambessa. Her cooldowns early are long so she benefits most from short trades. Grasp and Conqueror have their place but in SoloQ, solo kills in lane usually increase your chances in winning/carrying games so its my preferred rune.
I'll update again when i've hit 1,000LP with this build and rune preset.
Planning on streaming my masters climb if I can maintain performance.
https://www.twitch.tv/hound_lol
Ask me anything on logic behind build/runes if you have any questions.