While already plenty strong, Skullclamp reaches ridiculous heights if you sacrifice your 1 toughness weenies
And then not much...but now in Standard right now we've got a better version with ward 2 called disguise cloaking is a better manifest from Murders and we just got manifest dread in Duskmourn
But just three colors, no more Black or White
Whilst you do need to meet the requirement of having three legendary creatures on your side of the battlefield, this requirement is actually a bit easier to meet than it sounds because Kolvori herself counts towards that, meaning you only need two additional legendary creatures by her side
All told, we have a lot of ways of putting counters on things and then increasing the number of counters on them
Meanwhile, in Pioneer, pairing the legend with Field of Ruin makes it even stronger as a control finisher