I was thinking about flash crowding out summoner spells, being the uncontrolled king, and all roles prob take flash and 
ADC 
Support 
/
top and mid and 
for jungle Unless you are pentakill and you take . To be serious, I was thinking of a summoner spell that instantly reset all basic ability cooldowns. I was assuming it would be on a 300 second cooldown or 5 minutes.
that summoner spell would be far to game breaking.
Would it really incite enough people to take it over Flash though? Assuming the enemy team capitalizes on you not taking Flash, rolling without it would be deadly.
While what you suggested has both offensive and defensive purposes, Flash does as well, and there would be more situations where Flash would be more valuable than something that resets basic ability cooldowns.
I would imagine that a majority of players would keep flash regardless, and use what you suggested as their secondary summoner spell as well. Not only that, but that summoner spell is basically a reset on all abilities, something that is kept on only a few champions such as 
.
Even though the cooldown is 300 seconds, wouldn't some champions make too much use out of that summoner spell?
having his basic abilities reset would call for even more nerfs.
It makes champions twice as slippery and twice as sticky as well.
Double slows, stuns, roots, knock ups, blinds, etc. on some champions would be unbearable, such as champions that are already mobile. Double knock ups would be especially deadly since the duration of those are unable to be reduced. Double gap closers / escapes.
keeping you trapped in an even longer snare
forcing you to stay in that stun
condeming you twice
rushing you into a wall twice
and 
becoming more mobile than they already are
locking you down for longer than she should
getting a reset just like that is self explanatory
pulling twice in succession
Fear, silence, fear, silence...
Double the poles
I doubt it will make a majority of champions / players take it over Flash, except in a few cases. A summoner spell like that would crowd out all the other summoner spells by a massive margin compared to Flash.
Flash is in a rough spot.
Mobile champions will dominate further if it was removed. Immobile champs will obviously suffer.
Even Flash having it's own summoner spell slot and leaving 2 free slots open would be way too strong, since a plenty of champions having an extra summoner spell would increase how deadly they are by ten fold.
