Well Riot does like to change things when they bring gamemodes back. Sometimes a mode that was previously on the Howling Abyss would instead be on the Rift. When URF came back some numbers were touched like those of shields and heals. What ideas do you have that would make a second coming of ascension better than the previous one?
I'm sure we all (or at least those of us that cared about them) hated the fact that some of those icons could take up to 20 games to get even though all you need is one good game to complete the requirements.
As far as in-game mechanics go, I'd like to see some kind of changes made to make the fighting more dynamic. Perhaps once one of the relics is claimed, a Skarner-like area is designated for the team that captured it providing stats for all allies inside. Maybe capturing a relic would give the team that captured it some kind of short buff (ie left one gave MS for 20 seconds, right one gave armor/MR for 20 seconds, bottom one gave AD/AP for 20 seconds). Perhaps each platform you teleport to could have a stat associated with it that each player that teleports to it would receive until they die? How would you feel if the game was even more focused around the ascendant, so much that whoever kills the ascended player becomes the new ascendant, meaning there's always an ascendant after the first Ascendant Xerath Bot dies? Heck, if you don't like any of these ideas then how do you feel about Hexakill Ascension?
If Riot brought back the mode with no changes to it I'd probably play 2-5 matches then stop because I felt like the objectives and combat had little to no depth the first time around. Maybe that's what people liked about it, but the game felt to me like it was the base idea for a gamemode that Riot intentionally went conservative with on their first implementation.
and 
whilst every time you played URF the game always had 
or 
in it.
is god.
