Flask needs to be removed or Changed!
Flask is probably the single most broken early game item in the game. For the same reason Riot made caps on HP/MP Pots flask should be removed or changed significantly. It makes champions that are supposed to have a weak early game completely ignore the "weak" part and easily out sustain and out damage their counter part. Here is math behind why no one should ever go mid (and possibly top) with Dorans ring or Blade over flask (even non-mana champs, Just pots instead of flask).
Over all Assumptions, Average spell costs 75 MP. Average Damage is 60 + .6 AP/AD on spells (at lvl 1). Assumed base mana pool of 275. This does not take into account the HP/MP u get from lvling, but we are assuming they are the same for both champs (which they nearly are for most mids) which makes it negligible.
Flask + Pots Restores 120 HP and 60 MP, 3 Charges
- you can buy 3 more pots, usually its 3 HP pots or 2 HP and 1 MP (we will use this for the calcs as its the most used). = 120 * 3 +150 * 2 = 660 HP = 60 * 3 + 100 = 280 MP
So taking in our assumptions we get: 660 HP / (60 + (.6 * 15))AP = 9.56 Spells worth of HP from an opponent with Dorans Ring/Blade (275 MP+280 MP)/ (75 MP) = 7.4 Spell casts
Note: none mana champs would run 5 HP pots, being able to take more damage. and unlimited casts.
Dorans Ring + 2 Pots 60 HP 15 AP 3 MP/5 4 MP on kill
So assuming you get every single minion kill with 6 in each wave (yes i know there is 7 occasionally but 4 MP every few waves isn't going to change anything), and assuming until your first back (roughly 7 waves some times more depends on scenario), with 30 seconds between waves.
60 HP + 150 * 2 = 360 HP 4 * 6 * 7 = 168 MP 3 MP/5 * 30 * 7 = 126 MP 168 + 126 = 294
So taking in our assumptions we get: 360 HP / (60 + (.6 * 0))AP = 6 Spells worth of HP from an opponent with Flask (275 MP+294 MP)/ (75 MP) = 7.5 Spell Casts
Note: the math for the blade would show you being able to take a fraction of a spell more (but obviously have unlimited casts)
So what does this mean?
Well if its Flask VS Ring, then Ring can take 6 spells, but Flask can cast 7.4 spells (Flask can Kill Ring) Flask can take 9.56 spells, but Ring can only cast 7.5 spells (Ring cant Kill Flask)
Flask both out sustains ring/blade, and out damages ring/blade in the early game. Making "weak" early game champs actually stronger than their counter parts that are almost always running Dorans.
Edit: some of the math looks funky cause of the stars im using for Multiply By, ive tried fixing but it doesn't seem to work correctly