Cleo has been playing "Summoner's War" since it came out. He's a huge fan.
1. Neal, the Light Fairy
Those of you who have been playing Summoner's War for a while should be very familiar with this pick, given that Neal has been a popular pick among support creatures since the very beginning.
Everything in her kit is aimed at sustaining her allies, with her one attack having the possibility of a stun. That measly attack isn't what makes her good, however. The real star of her show is her immunity ability, Holy Shield.
For a whopping two turns, Holy Shield will make a target ally immune to damage and debuffs. This sets you up for all sorts or good plays, allowing the target monster to continuously do damage without penalty for those two turns.
On top of her immunity, Neal also brings a heal to the table. It's simple enough, restoring health to a target ally while removing any debuffs they might have accumulated.
As for possible rune sets, I've found that Energy runes x2 two paired with a set of Endure runes helps her to self sustain much longer, effectively keeping allies sustained longer.
Neal, the Light Fairy, is definitely a first choice.
2. Belladeon, the Light Inugami
Unsurprisingly, you'll see a few light creatures on this list, as they have a knack for being great supports. What's special about Belladeon, is that the light inugami is a strong offensive support.
Belladeon's first ability, scratch, does a rather average amount of damage, at best. However, given that it hits properly, it will reduce the enemies defense by a tremendous amount—successfully allowing your other creatures to do them in.
Seize, it's next ability, does quite a bit more damage than scratch. That fact is good well enough on it's own, but the buffs it removes from enemies takes the cake. Find yourself facing an enemy with a shield that you just can't seem to break? Seize. Enemy no longer has a shield and it has taken a significant amount of damage.
Immobilize is what really compliments Belladeon's kit. Not only does it restore up to 50% of your allies health, depending on how much you've upgraded the skill, but it also fills your attack bars by 30%. It's also on a relatively short cooldown, given the skill type, so it can really get you out of a bind.
For runes, the light inugami has quite a few combinations. A much safer combo would certainly have to be Energy, Shield, and a Focus or Violent set. Although it really is up to what works best for you, as the player.
Overall, our dear Belladeon is a great stand-in up until the very late game, where some strong contenders can come into play.
3. Megan, the Mystic Witch
Megan is pretty well rounded as an offensive support, yes, but her specialty would be anything having to do with offensive PvP. Most notably, she's best in guild battles, the Arena, and couple B10 dungeon builds. What really accentuates her prowess in PvP is her leadership skill, which increases the attack power of allies in the Arena by 21%.
Crow Summoning, her first skill, does a pretty good amount of damage over time for one turn after she uses it. It's not much, but it's a buffer for when her other abilities are on cooldown.
Toad poisoning, Megan's next ability, nearly speaks for itself. It removes a buff with a high chance to prevent the enemy from receiving buffs for the next turn. This has great potential in boss fights, especially for those dungeon bosses that have a habit of becoming too buffed up to defeat quickly.
Her third skill and by far the one that makes her the most support like is her Spell of Strengthening. It's a buff on allies that increases their attack bars as well as their defense and attack power. When paired with things such as Perna or Lushen, it can make for a powerful team comp.
When it comes to runes, speed is most important. You want her buffing and debuffing as quickly as time will allow. For this, pair Swift runes with any other rune set. For example, a Swift and Energy pair.
If PvP is your thing, Megan is a must have for your team!
4. Chloe, the Epikion Priest
Much like her elemental counterparts, Chloe is easily viable as one of the best supports in the game. While all of the Epikion Priests could have easily made up this list alone, I specifically chose the fire variant because of how aggressive her sustain is.
Absorb Mana, the first skill of every Epikion Priest, scales with your Priest's max HP. Meaning, the health she has, the more damage Chloe will do. On top of that, it's vampiric in nature. It'll restore health equal to 30% of its damage.
Chloe's next ability, Fill, is her main heal. It will automatically target two allies that have the lowest health and heal them for 25% and 15% health respectively. The cooldown on it isn't all that long and this is great when paired with her next ability.
Fanatic is by far one of the best spells for sustain in the game, and Chloe is the one to wield it. To start it makes all allies invincible for a turn, making everyone take a grand total of zero damage per that turn. For the next two turns, all allies have immunity. While the immunity itself can be dispelled, it will protect allies against harmful effects if it isn't.
A set of Energy runes paired with any other combinations would do best for Chloe's sustain, but will also help with the damage of her ability, Mana Absorb. Otherwise, a speed/HP build would be recommended.
While all of the Epikion Priests are viable, Chloe is by far the most aggressive and best with her sustain!
5. Delphoi, the Wind Undine
Delphoi really doesn't get the credit she deserves as a support creature. Most only focus on the Water Undine, or maybe even the Fire Undine, but in reality, they're all great creatures to have.
Starting with Lightning Drop, it is purely a damaging ability, until awakened. Be that as it may, it still has a higher base damage than some of the other supporting creatures basic damaging spells. When the Wing Undine becomes awakened, into Delphoi, this ability also becomes a debuff to attack if it critical hits.
Mind Shock is incredibly useful virtually everywhere. It does a decent amount of damage—but here's the kicker. It sets the enemies abilities on cooldown. There is no place where this skill isn't useful.
Much like Neal's Holy Shield, Spirit's Blessing also grants immunity for two turns, but that isn't all. On top of the immunity, the ally is wiped clean of any and all debuffs while getting 15% of their health restored. That might seem like a small percentage, but it might just be the bit to turn the tides.
A pairing of Swift and Energy runes would be an alright start for our precious Wind Undine, but not the best. Once able, a set of Violent and Will runes should be put on Delphoi. Be sure to pay extra attention to her defense, HP, and speed stats.
Overall, Delphoi is a fantastic catch for those who are lucky enough to get her in a summon.