So just a small idea, but so when you die with a Guardian Angel and it says "Resurrecting." What if with robot champions, such as Blitzcrank or Orianna, when they die they don't "Resurrect" but they "Reboot." I feel like many people who main robot champions will really appreciate this change. 
Chembaron Yamada2 votesThinking about it: I think the general idea of such item interactions is really cool and interesting, but it would be wasted on guardian angel, since they don't really build that item.
Look at newer item interactions from champions, usually they have quotes for items they would actually buy.
That being said, maybe we can suggest some other interactions.
if the spell shield gets triggered
"Energy barrier down!"
when the slow area on ult triggers
"Release cooling liquid!"
TheticalChunk1 votesThat's kind of the idea I'm getting across that different items would say things to different champs, but the first thing that crossed my mind was the robot champs.
Chembaron Yamada1 votesBuuuuut who builds Guardian Angel on Blitzcrank or Orianna?
SomethingAncient1 votesA troll-crank would :3