Its most often used to finish off an opponent who was foolish enough to drop below 5 life, though it can pop a creature, so it qualifies
It doesn't matter whether a Giant, Wizard, or spell you control deals the excess damage, only that excess damage was dealt and that one of those three things dealt damage to the creature or planeswalker at some point during the turn
Youll still have to pay half as much for a CE/IE Chaos Orb than you would for an Unlimited Orb, and thats mainly due to its popularity in the Old School format
Assuming you bought each product when they went on sale (not 10 months later after they are out of print and potentially more expensive), how much would this set you back
You havent seen it until you see it in 6-D
One of the strongest decks of the current format, however, will be leaving the game forever, and thats the Rapid/Strike Inteleon/Urshifu deck