While playing a game yesterday, the enemy Ziggs was wrecking us. So, we tried to focus our fire on him. Unfortunately, the enemy Zilean got his Ultimate on the Ziggs. While we were waiting for Ziggs to return, we were taking fire from the enemy team. When he revived, he used Zhonya's Hourglass! It seemed like we were waiting forever for him to be target-able, and the rest of his team cleaned us up.
How long can any one champion remain untarget-able or in stasis in a row and under what circumstances can this occur?