Reproduction steps: 1. Deploy Angel of Restoration and Sun Blossom. They both have abash. 2. Attack one of them. 3. The charmed champion will now be able to attack the other one as long as he wants until charm expires. @Sokolov Was it changed in order to prevent 2 champs with abash / charm / flourish from keeping an enemy champion forever locked in a dance between both or is it simply a bug?
I don't think it's a bug. You just can't attack the champion that charmed you. Same with fear. It checks for the user of the ability. There is something like "this champion is charmed by Etherielin's Sun blossom (some number here), it cannot engage, has -3 damage and cannot attack the champion that charmed it" on temporary effects in game. WAI imo.
That's not the case with effects like horrific aura for example though, which is why I believe it to be a bug. They're different in terms of duration (permanent passive vs temporary active) but the mechanics are technically the same.
I don't know why it's different, but I'll call it a bug. Still, it sounds like it's a bug that's been in the game forever and is rooted in old code, don't expect a fix any time soon.