Supports in warframe are warframes that can in some way help teammates, not just kill everything. Almost all warframes have some kind of ability like this but they still can't be counted as supports. I'm only listing the abilities and then it's up to you to decide which frames are supports or not.
Examples on this kind of ability: (think i got all but correct me if I'm wrong :P)
- Banshees Sonar, show enemies weakspots and increases damage dealt to that area.
- Frosts Snowglobe, shields teammates inside from projectiles.
- Lokis Switch Teleport, can switch places with a downed allies.
- Lokis Radial Disarm, will force ranged enemies to go melee.
- Mags Shield Polarize, can grant 50% shield to teammates (if maxed).
- Rhinos Iron Skin, keeps Rhino alive while he helps downed teammates.
- Rhinos Roar, can grant up to 50% more damage to all teammates.
- Trinitys Well Of Life, grants teammates health.
- Trinitys Energy Vampire, grants teammates energy.
- Trinitys Link, keeps Trinity alive while she helps downed teammates.
- Trinitys Blessing, grants teammates full health, shields and ivulnerability.
- Volts Speed, can grant speed and melee attack speed.
- Volts Electric shield, can protect players and give them 50% electric damage.
Abilities that can control enemies, stuns, knockdown, stagger and lift. (more?)
- Banshees Sound quake, stuns enemies (CC).
- Excaliburs Radial blind, stuns for 5 sec (CC).
- Frosts Freeze, can stun for 10 sec (CC).
- Frosts Avalanche, blinds and freezes enemies inside (CC).
- Lokis Radial disarm, (though only against infested) will stun or knock down enemies (CC).
- Mags Pull, can pull enemies away from teammate (unreliable CC)
- Mags Crush, Lifts up enemies (CC).
- Nyxs Chaos, makes enemies attack eachother (CC).
- Rhinos Rhino charge, can knock down enemies (CC).
- Rhinos Rhino stomp, stuns and knocks enemies down for a duration of 9 sec (if maxed) (CC).
- Saryns Miasma, stuns for approx 3 sec (CC).
- Vaubans Bastille, can hold enemies for 15 sec (if maxed) (CC).
- Vaubans Vortex, can pull enemies away fom teammates (CC).
- Volts Shock, can stun up to 5 enemies (unreliable CC).
Why A Good Support Is Needed
Even though many players think they are the best the fact is that this is a team game and if you do fall down your teammates are supposed to be there to help you up again and give you a pat on the back saying "Get up on that horse again m8 ;)". Real support players like myself have this programmed to their spine and will do this in any and all situations just cause we like helping our team. those who think a Support aren't needed isn't playing a hard enough mission (or missions of other type). Someone told me "you don't need a support, you just have to kill everything" and this is exactly what I'm talking about... have you guys never gone down in a mission proved to be a little too hard for you? or have you completed each mission without any problem? i don't think so... everyone has gone down and had a teammate there to save you. IMO we need more supports and make more use for them.