Cross Posted from my Summoner spell thread from several months ago.
Barrier, Barrier started off in ARAM as the MUST pick spell beside Flash. It was then moved to SR, where it became the MUST PICK for ADC's However, since Heal has been buffed at the beginning of Season 4, Barrier has become outclassed in almost all cases. I suggest changing it to a support/tank pick that is contested by exhaust.
TANK'S REJOICE! NEW -> When used, creates a barrier on target ally champion closest to your cursor (within 200 units) granting them a shield that protects against 50+10xLvl and grants 4xlvl% of your total Armor and Magic Resistance for the next 2 seconds. (Numbers would be capable of changing) 180 second cooldown
This turns Barrier into an actual BARRIER by providing CLUTCH resistance bonuses and a very SMALL (230 Hp at level 18) shield to try and save an ally in a manner different from Heal. it's combat usage is also capable of helping save someone from a gank, that heal or exhaust may not be able to do. Exhaust would still be powerful because of it's ability to reduce damage to EVERYONE, and reduce the resistances of the target. Tank supports would likely take Barrier, while squishier supports would take exhaust.
Clarvoyance: once considered a must pick spell for supports, it used to have a cooldown as low as 45 seconds. This led to binary play where the enemy jungler would always be seen and could permanently be tracked through the jungle. Riot then nerfed CV, and it fell out of use as it's ability to scout was not as good, since it wasn't up enough to constantly track the enemy team. Since the nerf from 45 seconds to 60, and a host of smaller minor changes, CV has become a "troll" pick, especially since the removal of Elesia's Miracle. (RIP) CV has further been pushed out because of the arrival of the blue Trinket.
ALL SEEING EYE SEES ALL! NEW: When used, all enemy champs are revealed for 2 seconds (Similar to TF ult first active) 90 second cooldown.
This now gives CV an incredibly unique type of vision, that no trinket can replicate. This could make CV a VERY desirable pick in competetive because of it's ability to locate anybody at any point in time.
Clarity: Clarity was once also considered a solid pick for more utility AP champs as champs could sustain their DPS. In fact, now that mana regen is much worse, Clarity could potentially become a decent pick for mana based mids that need a tiny bit of mana to escape or to secure a kill. HOWEVER, Since summoner spells are generally picked for their more IMMEDIATE combat usage rather than anything else. So, my thoughts for the change are one that I think i'd seen on the boards before, that I actually incredibly like.
MINI RAPID FIRE MODE! NEW: When used resets all non-ultimate cooldowns and reduces the mana costs of all abilities by 75% for the next 2 seconds. 210 Second Cool-down
Thematically, this is a person meditating and gaining insight and ability to use all their skills again. It also allows for some incredibly flashy plays, Granted this could potentially be way over bearing, and may not be a healthy addition. However, because it would be a worthwhile spell to pick up in this manner, it could actually be balanced by changing how much it reduces non-ultimate cool-downs by, or how much the mana costs are reduced, or for how long they're reduced. In any situation, it becomes a worth while spell to use on some/many champs.
Cleanse: Cleanse has been niche pick because of it's clutch CC removal and CC reduction, but it loses out to QSS overall. This is because QSS not only gives defensive stats, builds into a hybrid defensive/offensive item, but removes ALL debuffs, not just most CC.
TRULY CLEANSED: NEW -> Cleanse Now removes ALL forms of CC, and grants 1 second of CC immunity upon use: 150 second cooldown
THis now makes cleanse a true pick against CC heavy teams, and actually has something that sets it apart from QSS in that Cleanse removes ALL CC (Including suppressions) and gives a 1 second immunity. QSS still removes Debuffs like Grevious wounds and DoT spells Like Malefic Visions, but now, cleanse can actually prevent the stunlocking and CC chain that the current cleanse and it's 65% CC REDUCTION does not. Doing this make Cleanse desirable against CC heavy lanes, or against WW and Malzahar (Note that it doesn't stop the damage, just teh CC)
Revive: Revive has been considered the absolute WORST spell in the game since season 1, it's been left in because it actually say pretty common usage with the cheesy revive teleport homeguard Karthus, and a few other champs that could pull off that combo. However it's 9 minute Cooldown has always made it a terrible pick up and a waste of a summoner spell.
BRINGING IT BACK! NEW: Revive's cooldown now scales with level beginning with 555 Seconds (9 minutes 15 seconds) and reducing by 15 seconds every level (level 1 cooldown unchanged of 540 seconds)
This means that at level 18, Revive has a cooldown of 270 seconds, or 4 minutes and 30 seconds. In other words, a spell worth using.
Ghost: This is honestly a decent pick, and actually I don't really have anything to make it better or worth picking over flash, since flash's terrain hop will always be too good to give up in most cases. The only thing I can see worth changing is giving the user 75% slow resistance while ghost is active. Mainly because the powerful slows in the game make people using ghost somewhat kite-able.
,
and 
) only taking up 0.3% of the chart. 0.3 percent! for FOUR spells!
is so essential that they might as well just give it to everyone for free! Summoner Spells could be so much more immersive, with greater variety to choose from. Around half of the spells we currently have rarely see use, while Flash is the go-to spell that everyone is obliged to take because of its usefulness. It would be very interesting to see how the other spells could be touched upon, buffed or tweaked in order to become relevant.
), and there are probably some other ideas that could be made into new spells.
should take up more than 1/5 (since jungles ALWAYS take it, and now other lanes take it too), but seems to be taken less than 
.
