User blog comment:NowItsAParty/Truly Ascended/@comment-3542156-20140917133128

Controlling and capturing the relics. If your team can swiftly move between relic points and quickly secure them, you can easily come on top. Even with an Ascended on your team, this should be top priority since focussing on getting kills will cause your Ascended to get killed more quickly.
 * What is the single most important task/objective to have in mind during Ascension?

I'd say champions with good vision and/or disruption. Keeping your enemy away is key here, although being able to isolate or lock down enemies for your team to pick off is good too.
 * What champions are best at completing/controlling these important tasks?

Getting the Ascended on your team is a great benefit, indeed. However, many of the players that get the Ascended think they are powerful enough to take on the enemy team solo. Therefore, once you get the Ascended in your team, stay with it at all times to protect it.
 * Are the any secondary objectives or strategies that often seem to be overlooked?