In short, you will be an utility singed.

The main purpose of this build, is to annoy ennemies, go to allies very fast to R them and defend objectives, since zilean lacks heals, shields and is very squishy other builds tend to favorise tankiness and mana, and they're right, but you can have both WITH extreme MS to give you extreme map control. I have had hard time being usefull with zilean when using normal support builds because you're just a walking revive, but with this build, you can be worse than singed, tanky and speedy, but without the damage.

With just swift boots and dead mans plate, you outrun nearly anybody who doesn't have swift, it's great for just following people around, letting them waste their mana with skillshots and if they go your way, you just E and you're out of range again. Predator is good to go back to lane fast in early, and go to objectives fast overall

The main strength of zilean is the ability to roam without care because of the huge disengage he has with his bombs and speed with his E, when my ADC backs i usually have time to ward the ennemy jungle and roam mid, then come back to lane, and if the ennemies follow me it's better.

You will be able to put ward very fast for objectives and/or annoy the ennemy jungler.

Engage
E on ennemy > Q > W > Q > E on ennemy
this is your most basic combo, go to grass, then use this against the supp or adc, it's hard to do this without taking damage in plain sight.

E on yourself > Q > W > Q > E on ennemy
Don't use it early, i think it's too risky and wastes too much mana in. After your first items thought use it freely

Disengage
R > Q > W > Q > E on ally
Put the bombs on the dead ally so he can be safe when he revives

E on yourself > Q on yourself > W > Q on yourself > E on ennemy
You can put Q ahead of you for the first bomb,for the second one try not to touch ennemies or you'll just run to your death

idk be crafty, his kit is simple but is very versatile depending on the situation and matchups

DONT FORGET,
THINK OF YOUR BOMBS MORE LIKE A CC, NOT A DMG SPELL. If you are used to just throw bombs to do a little damage, you'll run out of mana very fast, try to AA instead to proc your supp item.

Use your Q to get vision like maokais little trees, that's what will keep you alive when roaming around

Q youself if you know that you will get jumped on !!!!

Most times, just putting 2 bombs apart will scare people, even if it doesn't stuns them and do no damage lol, use it to control large paths like river.

Time your abilities, put E after the stun, put the 2nd bomb near the end of E, with right timing you can CC forever.

Don't forget to help your jungler at larvaes if you are ahead and finished boots.

Try to know at all times the ennemy junglers position so you can deny drakes/larvaes

Don't get cocky and go alone 80% of the game, if you're not used to speed or the ennemies has high kill potential like nocturne/twisted fate, stay more with allies

I'm not the best zilean so please give feedback on builds/combos/situations so we can get better, faster and stronger with speed zilean