About shields, if you have Valkyrie and she puts a shield up, then in the same team you have Krisk who can also cover everyone with a shield, and you equip a shield set on someone else does it just use the strongest and ignore the others?
Shield set is different from the ability. It doesn't get overwritten by anything and, apparently, it also stacks if you have multiple people with it (though I can't personally confirm that). It also stacks with shield abilities.
Champs with shield abilities, on the other hand, *will* overwrite eachothers shields added by shield abilities *if* the duration of the new shield is longer than the existing one, regardless of its strength.
Yep, you'll notice in on screen info page/ buffs, debuffs list above every champion that the artifact shield buff looks slightly different than the Ability shield buff.
And as for the above comment on ability shields being overwritten by higher duration, this is sortof incorrect. For Shielding abilities that have a duration of (2) turns on target, this buff will indeed replace another shield ability with a duration of (3) turns on the target. I can't say if this is true for ability shields that have a duration of (1) turn on the target.
And yes the artifact shield sets do stack, they base the 30% off of the shield set wearer's own base HP stat.
