In Progress! Completed chapters are marked with bold. To be done ones are marked with italic.
-Io's power scaling on every map
-Best team compositions / Worst counterpicks
-Niche tips and tricks
-Cards and Items
Io has been around for a while, and has already captured hearts of many. With the unique ability to fine-tune her healing to extremely precise amounts, she is becoming a very popular pick that can rock with any team composition.
She is super versatile and a well-rounded character, bringing a little bit of everything to the table. She really is a jack of all trades, but master of none, and should be played as a very reactive champion. Unlike most other supports, Io can command a very strong presence in fights, but her greatest weakness lies in being extremely team dependent.
Io's talents are : Life Link, Goddess' Blessing and Sacrifice.
Life Link : Luna now heals allies near her. A nice talent if the enemies have a lot of spam or area damage that can decimate your Luna in seconds if you try to place her on point. With Life Link, you have a personal bodyguard for you and any nearby allies, that can also double as a point healer/capture once you decide to dive in with your flank or damage.
Goddess' Blessing : Allies you directly heal take a quarter less damage from any sources. This talent really shines through both early and late game, due to the fact that Cauterize counters heals - but damage reduction is always persistent. This build does yield less overall heals than Life Link (about 30% less stat-wise), but makes up for it as it blocks a whole lot of damage (all the while you heal them).
Sacrifice : If you die while Luna is active, she is sacrificed, you take her place and heal. Heavily overlooked talent that isn't all that bad (who doesn't like a second chance) - the reason it's very rarely used is because the first two talents bring more value during the fights, even if you rock a more aggressive play-style.
Io's power scaling on every map:
Tho shy at her release, Io plays grew tremendously as time passed by and players started maximizing her potential. Foolish be that off-tank who dares flank an Io player with good positioning, as he'll just be yeeted off the map to shame eternal. Nowadays, it's not uncommon for Io's ultimate ability to make or break games, as she eliminates an unsuspecting enemy. or two (even going as far as getting a full team wipe myself (with my dear Seris friend <3))
Cards and Items:
Io has a very niche selection of cards to suit your play-style. These are suggested loads for first two of her talents that you can base your builds around, and then fine-tune them to your play-style. There's no direct builds for Sacrifice, as either of the two main builds (or combination of both) works perfectly for it.
With that being said and considering the total time you will be spending healing allies with Moonlight, I strongly suggest to keep Swift Arrows on either IV or V - it's a very powerful card that sure is a lifesaver; and have Restored Faith anywhere between III and V (I personally think anything over III is countered very heavily by Cauterize, so the points went in other cards that have no direct outplay).
Increase allies' Movement Speed by 32% while they are being Healed by Moonlight.
Heal for 30 every time you Heal an ally with Moonlight.
Reduce the Cooldown of Luna's redeploy by 0.30000000000000004s.
Reset the Cooldown of Lunar Leap after dropping to or below 45% Health.
Increase Luna's deploy range by 40%.
As Luna gains a healing aura, Life Link build revolves more around personal survival and improving all your abilities. Spirit Arrows III and Broken Deity II allow you to constantly reposition Luna around, doubling her as a second healing ability. Since we will be moving Luna around a lot, we have Crescent III as a quality option if we happen to get caught off-guard by a flank.
This build suits defensive teams who can protect you and Luna.
Increase allies' Movement Speed by 40% while they are being Healed by Moonlight.
Heal for 30 every time you Heal an ally with Moonlight.
Generate 6% Moonlight for each enemy hit with Light Bow.
Sanctum of Faith
Regenerate 3% Moonlight every 1s while not using Moonlight.
Lower your gravity and increase your air control by 10% while using Moonlight.
With Goddess' Blessing, we need more up-time on Moonlight and a way to generate if faster once we run out of juice, hence Moonlight Garden III and Sanctum of Faith III. With this build, we also don't need to move Luna around too much, she can help with point captures, babysitting your backline from flanks or just guarding a certain area. Moonwalk is a one-point wonder much like Ying's Rewind, and allows you to double distance covered with your jumps if you need to escape or catch up to allies.
This build suits a more aggressive team and play-style.
As much as they are personal preferences, these are key items to keep in mind come to Io's play-style.
Gain 30% Movement Speed.
Reduce the Damage you take from Area of Effect attacks by 21%.
Reduce the duration and effectiveness of Crowd Control and Slows by 90%.
Reduce the Damage you take from Direct attacks by 21%.
Your weapon attacks deal 225% increased Damage to Shields.
Increase your Ultimate charge rate by 45%.
Nimble allows you to maneuver around fights, either to catch up to allies you're buffing to oblivion (32/40% movement via Swift Arrows), or for quick dance-peeking around corners so you maintain heals on allies without being exposed for too long.
Morale Boost gives you more chances to either yeet an enemy off the map that's trying to bring you down, or allows you to use this ability more literately to dodge some key ultimate abilities, as it does provide a very brief immunity that can save you from, say, Viktor or Dredge ults if you REALLY need to be alive.
Haven, Blast Shields and Resilience should be picked up if certain enemies give you more trouble than you're comfortable with.
Wrecker is very often overlooked with Io - but even Wrecker II allows you to apply a whooping 1.000 pressure pokes against shield-heavy compositions (with Io's very fast attack speed, you can quickly eat shields to land a stun with Luna if necessary).
Reduce the Cooldown of all your abilities by 30%.
Increase your Reload Speed by 60%.
Chronos does not benefit Io too much - chances are if you get caught off-guard, 3 seconds off your Leap for whooping 2400 credits isn't doing you any justice; neither it helps Moonlight's resource bar in any way. You are much better off grabbing another item from the list above.
Deft Hands also shares the same reasoning - there are other items that give Io much more value, and considering she already has a rather fast reload animation, it's just not needed.