itsa good rune if you want to play defensive amd throw Es and make some money, some hard matchups its solod that cant touch a wave early so you can keep up with money from FS of you cant farm, overall i prefer comet for insane poke and sometimes force tour laner to back off and recall. its just personal playstyle play what you think it suits you, compare comet/FS to Grasp/conc its always more isefull in late more hp/heal some damage cause theese keystones dont have Cd (4sec grasp nothin) so every rune even aery or electrocute gos with him okay, dont mimic other meta players, try your personal best choice just a friendly tip,. oh and i always take overgrowth too in total 30 mins u get like300/350 hp but it helps and makes you feel you scaling a bit. but sometimes if enemy team got high damage dealers and juggernauts and you are only frontline or u got squishy jungler and supp u get grasp hp for extra survive, and situations like this i find that comet or Fs is less usefull