Build Overview

This is a fairly self-sufficient and versatile build, focusing in equal part on aggression, mobility, ability impact, and survivability. I've found it most handy for generally roaming with a more aggressive comp.

Crest Options

• Tranquility (Recommended): Thanks to the short CD and powerful healing throughput, Tranquility remains an amazing source of healing. Use this as often as possible with as many allies nearby as possible. In a pinch, it can be handy for an emergency heal, but don't save it just for that; you'll usually get more sustain value using it off CD.
• Reclamation (Teamfights/Mass Cleanse): A mass cleanse button, even on such a long CD, is very impactful in big team fights. Particularly good if your comp has a lot of self-healing or tanky characters who can sustain themselves, but it takes some more attention to detail to use it effectively.
• Silentium (Disruption/CC Counter): While Reclamation vs. Tranquility is based more on personal & team playstyle, Silentium is your counter-build flex item. Pick against characters with long CC ults and abilities (Gideon, Riktor, Narbash, etc.).

First Item

Wellspring should almost always be first. This gives you what amounts to an extra copy of your passive, letting it synergize and scale in much the same way with the rest of the build. Your massive mana pool & regen mean you can typically proc Soothing Waters off CD, so—much like Tranquility—try to use it as much as possible.

Alternatives

• Requiem can be good to start stacking early in a very aggressive comp. However, I've rarely found it worth building as a first item without outright Zerg rushing the enemy laners on sight. Even if I am building it early, I prefer to slot it in as a second or third item.
• Crystal Tear can also be considered a viable first pick for a more defensive, heal-heavy playstyle, but I recommend against this; it's a bit inflexible (since Wellspring is then basically required for a second item), as well as slower than it's worth until late game.

Second Item

Galaxy Greaves are the usual pick for the massive mobility and escape potential. It's just generally the most well-rounded option.

Alternatives

• Marshal is a solid flex here (in which case Galaxy Greaves should be your 3rd or 4th item). You'll see the most use out of this with a comp that benefits a lot from attack speed (Kira, Sparrow, Grux, Khaimera, etc.). This also works better if your carry is particularly aggressive or you're ganking a lot.
• Tainted Totem can also be slotted in before Galaxy Greaves (moving them up to 3rd) against heal-heavy comps. In this case, I usually flex out Crystal Tear.

Third Item

Note: this will also possibly be your fourth item if you slotted something before Galaxy Greaves.
Typically, I pick from two options here:

1. Megacosm is a big boost to magic power, doubling down on healing. It's also easy to proc Disintegrate by poking with your E.
2. Requiem, which can arguably be built earlier (see above). The magic power and haste aren't as strong, but you make up for it with more sustain, heal & shield power, and extra physical damage/lifesteal for your allies. Typically most useful in a very aggressive comp or as insurance if you're struggling to keep up.

Alternatives

• Crystal Tear can be slotted in 3rd if you want to keep stacking healing (or have a comp that benefits a lot from the added magic damage).

Fourth Item

By now, you should be finishing your core build. If you need an item, get it by the fourth. As with the third, I typically pick from two items here:

1. Marshal should be grabbed by the fourth slot if you're going for it at all and don't already have it. Good stats, great passive. Less good paired with carries like Revenant.
2. Windcaller is a solid flex. Tons of mobility and mana sustain, meaning you and your DPS buddies can just keep cruising around in a ball of death.

Alternatives

• Crystal Tear can once again be slotted early.

Fifth Item

Crystal Tear is just a handy all-around boost to grab by this point and (in the "normal" build) is my usual last item.

Alternatives:

• Timewarp gives more ability spam, which Phase just scales very well with at a baseline (especially with Wellspring). Your CDs are short enough it's not necessary, but it can offer a pretty nasty uptime boost if you're being aggressive enough.

Other Item Options

• Dynamo is great for consistent ganks and easy to proc with your E.
• Tainted Scepter helps shut down healing and makes poking with your E much more nasty.
• Stonewall is a decent selfish pick if the enemy team focuses you with physical damage a lot and offers more sustain.
• Vanguardian has a bit less escape potential than Stonewall but is also less selfish (as it gives sustain for the whole nearby group) and offers both magical and physical armor.