My number one suggestion is Aces High Eddie.
Aside from his fury, (which theatrically is one of my favorites), he has for the most part but one standard attack (Shoot) and one power attack (Triple Shoot), both found in present. His past are shields (Guard and Reflect Magic), whereas his future is aid (Roulette and Rise). Granted, Rise is an aid/attack, but that ais not altogether pertinent for the points raised considering, IMO.
The problem:
Ill-conceived support Eddie
Aces has two heal options and a fairly weak attack as one might expect of a support character. However, his shields are self-targeting only and his yellow-yellow-red talismans do nothing for him as a support Eddie. Thus, you have Holy Smoke Eddie, who does considerably better damage in all respects, with half of Aces' support options (Rise). Moreover, Soldier's barrage and bullet trace remain superior to Aces' attacks, both in damage and AoE whereas Soldier's Endure (combined with their shared Roulette heal) makes soldier superior both in attack AND support, making Aces the Gunner version of RTTH when compared to Holy Smoke.
Poor standalone Eddie
When all toons have died before the Blood Brothers or LotB, I typically see little reason to panic with a healthy Holy Smoke or Carriage Rider standing. They can wage wars of attrition with powerful attacks and attack-heal counters that permit victory in standalone situations. Not all Eddies necessarily need to be standalone characters, but I submit they should be if they are poor support characters, especially when so armed with yellow-yellow-red talisman slots. Rise is Aces' only AoE weapon and with the energy cost, it neither is nor appears intended to be a reliable AoE attack. Shoot is anemic for a main single-target attack and the "critical" event that gives it a chance at reasonable damage is a pitiful 25%. Add insult to injury, there is no option to raise the event odds to a more respectable 50% or so. Triple shoot does have an option to raise the extra turn event from a pathetic 20% to a ridiculous 30% (at the cost of multiple skill shards, no less). Worst of all, it operates off magic damage, which utterly derails the physical/attack factors found throughout Aces' skill tree and his slots. This would be forgivable if the attack were profound, but it is nothing more than incidental damage to 1 or 2 characters, with a near guarantee that the damage will not be expanded with the squandering of talisman slots for blue, when everything else runs off ATK/SPL.
Suggestions:
1. Increase the damage in Shoot and/or allow a significant raise in event chance via skill shards (it's already like 99 skillshards to max this character... what's another 3?)
2. Magic damage on Triple Shoot NEEDS to go and be replaced by physical or special. You lose the complexity intended, but that complexity was ill-conceived, plain and simple. It's not worth the slots to invest magic for poor-performing attack, period.
3. Raise Triple Shoot's 30% maximum event chance (via hard-earned skill shards) to a minimum of 40 if not 50. This isn't multiple rounds of bullet trace, people... it's not like it needs to be that conservative.
4. Allow the shield(s) benefit(s) in past to apply to the team to better justify the capabilities of this character as a support Eddie.
By observing ALL of these suggestions you have a character who contends better against the likes of Soldier, Carriage Rider, or Holy Smoke without dwarfing their capabilities (unlike the inverse as it is now, which is a shame considering how rare this Eddie is). If conservative measures are insisted upon, then the either all of the Attack buffs proposed alone, OR the proposed shield buffs combined with all buffs proposed for one of those two attacks should be a must.
I will leave the opportunity for others to weigh in on the other toons and Eddies for the moment, so feel,free to add your suggestions or weigh in on mine regarding Aces High.