it would accomplish the goal of allowing him to have the utility-skirmisher role, whilst gutting tank Ekko, no?
The issue is that his early game would likely become atrociously bad without some kind of buffs to the base damages on his abilities to compensate for his loss of early game utility, but honestly that's something that could be done in reaction to him actually being really weak for a patch. No-one's going to miss him for a patch, right?
THE NUMBERS ARE FOR EXAMPLE PURPOSE ONLY
SLOW: 30 / 40 / 50 / 60% (scaling with level) >>> 30 + 0.05 AP% (60% slow at 600 AP)
Movement Speed: 50 / 60 / 70 / 80% (scaling with level) >>> 50 + 0.05 AP% (80% at 600 AP)
SLOW: 32 / 39 / 46 / 53 / 60% (scaling with rank) >>> 30 + 0.05 AP% (60% slow at 600 AP)
STUN: 2.25s >>> 1.25 + 0.002 APs (1 second per 500 AP)
This is the bit I would be most iffy on. A stun duration scaling with AP seems REALLY difficult to balance, since with a high amount of AP this stun could become SUPER long (3s+). It's probably wiser to make it scale with rank or just reduce it flat-out (2.25s >>> 1.75s)
The shield already scales 150% AP. Do we really need to buff that further to get Ekko to build AP? With 500 AP you have a 810 HP shield
No changes. Range scaling with AP would be SUPER awkward.
Honestly I personally feel that Chronobreak is pretty balanced on tank Ekko. The heal is pretty small (although the value with resistances is much higher) and AP Ekko can already pretty much fully heal itself. People complain about the ability itself, but lots of ults can be used as an escape - except those you get to choose where you end up. If you're playing tank Ekko and you're going deep, sometimes the ult isn't going to be somewhere safe for you to run to. It's not going to be somewhere safe in lane much of the time either. Honestly, I personally feel like much of the complaint about this ability is unfounded, and that the problems lie elsewhere in his kit. MAYBE adjust the numbers.