It's a long post, that's why I have it in another post entirely instead of posting it as a comment. It will also give more visibility :)
A quick summary of who they are. They are basically a Brother and Sister in one champion. The Brother is a more offensive type that deals damage while the Sister is there to aid him and their team.
Here goes my kit for the champion (don't worry I'm not changing a lot since I like your [original idea](http://boards.na.leagueoflegends.com/en/c/skin-champion-concepts/TiiM8l6s-cool-champion-conceptnot-boring-story-original-champion-kit-design) For all you people who haven't visited that post yet, it's where I got the idea from and am redesigning it):
**Passive: Life Bonds**
The brother and sister each have different health bars. They are displayed on top of eachother. The current healthbar being always below and the untargetable one at the top. Don't like Kled type of healthbar since it's different: you have to deplete Skaarl's hp first and then Kled's, but in this case both health bars are equally important.
**They don't regenerate health outside of the backline.** Potions heal both of them for half the amount each. Spawn as Brother.
They switch between Frontline and Backline. The player controls the sibling in the Frontline, the Backline is untargetable and invicible, and regenerates health. The Backline cannot be healed from external sources except from potions.
The siblings both share Items, gold, and experience. The sibling's HP switch instantly and don't lose aggro nor do they become untargetable during the switch.
Switching causes the siblings to silence themselves for 0.5 seconds, but they are free to move.
**My reasons:** *I made the passive a lot less powerful by taking away the automatic switches and giving a self-silence (kinda like Kled when he dismounts). I also clarified that they start with Brother in the Frontline.*
**Q (Brother): Protective Slash**
*Cost: 20 mana
Cooldown: 2 seconds
Range: 400 (same as Mini Gnar AA range)*
Brother attacks with his weapon in a cone in front of himself dealing 30/40/50/60/70(+50% of AD) physical damage to all enemies inside the cone and slowing enemies hit by 30% decaying over 2 seconds.
**Q (Sister): Helpful Hand**
*Cost: 60/70/80/90/100 mana
Cooldown: 14/13/12/11/10 seconds
Sister heals **Brother** and all allied champions in a cone for 60/70/80/90/100(+10/20/30/40/50% of AP) health. She doesn't heal herself.
**My reasons:** *Mini-Gnar's AA range seems appropriate for a poking ability that can serve for chasing or fleeing, and I've also set that range for the heal for convenience. Didn't change a lot here, except that 60 hp heal at all ranks was really low.*
*I have removed the heal on herself and applied it instead for Brother. In my opinion it is better since 1. Sister doesn't really benefit that much from the heal while Brother really needs heals and 2. It further shows the bond and synergy between the two, and the caring for eachother. (SIBLING LOVE jk xD)*
**W (Brother and Sister): Sibling Bonds**
The brother gains AD based on the sister's AP
The sister gains AP based on how much health they have healed at a rate of 10 AP for every 120/140/160/180/200 health to any allied champion (This shows up in the stat menu as "Practice: The sister has healed X amount of damage and gained X amount of AP")
The sister also gains AP based on the brother's current health ranging from 10-20/30/40/50/60% bonus AP.
**My reasons:** *None. I haven't changed anything here since I really like this passive, especially from Sister. Let me explain:*
*The scaling per hp healed encourages players to heal others, I think it's a healthy mechanic for the same reasons Veigar's Evil Power is healthy, but in a more team oriented style. BUT also because her second scaling is based on how healthy her brother is. If Brother is weak, than so is Sister, and this I really love a lot.*
For their E, it starts to get really different (I apologize if you dislike the changes but I want to hear your opinion, I stay open-minded for your thoughts. ^^)
**E (Brother): Backstep**
*Range: 125 (melee range)
Cost: 80 mana
Cooldown: 60/50/40/30/20 seconds*
When dropping below 15% health, resets cooldown completely. The ability icon will light up to indicate the player.
Dashes towards an enemy (from **very** short range) knocking them back a short distance and stunning them for 0.25 seconds, before stepping back 500 units (like Quinn's E but from melee range). Then **SWITCHES** to Sister and let's her use **E: Clothesline pinch** in the next 2 seconds.
**E (Sister) (Only after Brother's Backstep): Clothesline pinch**
*Range: 700 (her 500 range + 200 from the passive)
The Sister's next auto attack gains 200 range dealing 10/15/20/25/30(+80% of AP + 10% of AD) and stuns the enemy for 1.5 seconds. When available shows an indicator of the range (like Ivern's ranged AAs or Rapid Fire Cannon's passive).
**E (Sister): Daring Dash**
Cost: 80 mana
Cooldown: 50/40/30/20/10 seconds (10 seconds less than Brother's E)*
When dropping below 15% health, resets cooldown completely and the dash no longer requires hitting a unit to switch. The ability icon will light up to indicate the player.
Sister dashes forward 300 units. If she hits an enemy unit she deals 50 (+10% AP) physical damge, then **SWITCHES** to Brother and let's him use **E: Tackle** for the next 2 seconds. If she doesn't hit an enemy unit it sets the cooldown to 25/20/15/10/5 seconds (half the cooldown) but doesn't switch.
**E (Brother) (Only after Sister's Daring Dash): Tackle**
Knock an enemy back 100 units (very small distance) and deals 50/60/70/80/90 damage (+80% AD).
**My reasons:** *First, SORRY it's so long and complicated! :P But I thank you if you've read it entirely. This is the **SWITCHING** ability. I have removed it from the ultimate to make it more accessible and more usable, while also being able to give them another ability which they lacked. The passive switching when dropping hp is now set as a cooldown reset when dropping below critical levels. However mana costs still apply so it won't save them if they're out of mana.*
**TL; DR:** *I'll quickly explain: if you're Brother, he does a Quinn vault from melee range and switches to Sister, she then get an AA enhance for the next basic attack which also silences. If you're Sister, she dashes forward. If she hits someone, she switches to Brother and he can choose to Tackle, which deals damage and knocks them back a very small distance. If she doesn't hit someone, the cooldown reduces greatly but she doesn't switch.*
**R (Brother and Sister): Protective Atmosphere**
*Range: 1000 (same as Sivir's R range)
Cost: 100 mana
Cooldown: 170/145/120 seconds*
Shields every ally unit (including minions) in a wide area and both Brother and Sister for 100/175/250 (+50% of Sister's AP) (+10% target's max HP) for 3 seconds and heals them for 5% of the their max HP every seconds while the shield is active (loses heal when shield breaks).
**My reasons:** *It is basically a huge Locket of the Iron Solari shield with a heal while the shield is on.*
If you've read it entirely I thank you :)
Let me know what you think! Especially about their E, since that is their most important ability, and what gives them their identity of being two-in-one. They still don't have a name since the original didn't have a name :s
The numbers are only a placeholder (and for reference) and of course tuning would be necessary. ^^