Why do only certain champions with "executes" have indicators?
Think about
or
, both have execution indicators, which - obviously - show the respective champion a visual effect when their executing ability will successfully kill, but other champions with execution ultimates, like
and
don't have these indicators.
If you have no clue what I mean, let's look at Cho. When there is a champion near him with health under the kill threshold of Feast, a glowing red circle shows up around the champion. Basically when you're playing Cho'Gath and the enemy Ashe has a shiny red circle around her, go for that flash Feast.
Look, handy dandy pictures! http://i.imgur.com/QRY4Z.jpg
Conversely, when Zed activates Death Mark, if a spinning Razor Shuriken appears over the target, this means that the burst damage of Death Mark will kill the enemy. Just ult'd the enemy Annie and a spinning ninja star is over her head? Reactivate and don't look at the explosion of gore where Annie used to be.
Pictures! Things! Excitement! http://forums.oce.leagueoflegends.com/board/attachment.php?attachmentid=9756&d=1398479493
These are all fine and dandy, but there are other champs in the game (Garen and Darius, in particular) that don't get these markers. Ever play Garen and think "The enemy is at low health, but I bet I can risk the ult!" only to be met by an embarrassing whiff? Ever flash Noxian Guillotine onto an enemy only to be met with shame and dishonour rather than a delectable kill? Of course you have, why am I telling you?
TL;DR: Why do Cho and Zed have execute indicators, but Garen and Darius don't? It would be a nice QoL buff to both champions (who aren't exactly in the best positions right now anyway).
and as the circle glow under Sejuani, cho was decided to ult just to be smited last second and wasting his ult.