Lancer 4's E Kill condition pierces Avalon and revive spells
https://github.com/dun1007/fateanother/blob/bf44cdbd721138cddec80eddfd6f4f0452cfbd75/game/dota_addons/fateanother/scripts/vscripts/diarmuid_ability.lua#L144-L146
It uses a Kill function, hence revives such as Gawain's or Nero's do not occur. Not sure if intended.
For Avalon, Lancer 5's Heartbreak has an Avalon check so it cannot kill through Avalon.
Pseudo-heart break approach was a workaround for phantom entity issue where hero becomes invulnerable dummy with 0 health.
I think it is fair that Avalon blocks a death from health cap reduction below 0, but other revive mechanics should not work in the same scenario.
A bigger problem(as reported by Prick) is that double spear led by Gae Dearg is one shotting everyone below two spear's total damage whether target has defensive scroll up or not, because the kill condition is malfunctioning based on current health rather than max health sometimes.