[{quoted}](name=Alexander Keith,realm=NA,application-id=3ErqAdtq,discussion-id=pGsQX4W3,comment-id=00000000000100000000,timestamp=2015-08-17T02:42:52.497+0000)
If relic shield only healed enough to negate the damage from spellthiefs it'd be totally meaningless.
Spellthief's has a pretty significant impact. The fact that you don't notice it is your problem. Adding 15 damage to Sona's level one Q + Auto is huge. Adding 30 with frostfang is also huge.
And spellthief is still the best in terms of gold generation by a long shot.
spellthief only adds 10 magic damage and Sona's great and all powerful lvl 1 damage is 18+40+20+10 magic damage + auto... so she does 88 magic damage, that gets reduced by your 30 starting MR plus whatever an auto will do at lvl 1. Unless she build pure AP runes and whatnot and even then you can just add at most another 30~45 extra magic damage that once again will get reduced by your starting MR.
Spellthief is the best in terms of gold generation while the laning phase starts and only if you are able to constantly poke the enemy. The instant you cannot poke the enemy safely or the laning phase ends then
this line of items will give you more gold since you only need to be near a minion dying to get the gold without needing to put yourself in danger