User blog comment:SpotRudloff/New ARAM anti poke item/@comment-5266525-20130605153424/@comment-5305901-20130605165745

As mentioned before, their complicated explanation and usage causes they won't be any good for the team that has the poke. Otherwise they could use it to get out of hard situations when fighting. If you mean stacking the strength of the shield, of course there could be just fixed amount (like 120 + 20 x level health over 5 seconds). But this way the heal is dependable on the amount of poke the enemies do.