Area wide spells

[SUN-Leekie]

Description: There are events where a spell is supposed to be on every player in a zone at a given time. Examples:

• [x] Fall of Magtheridon: Trollbane's Command & Nazgrel's Favor is supposed to be on every players in Hellfire Peninsula & its dungeons for 2 hours. Players joining the area, will gain the aura and lose it when leaving.
• [x] Hellscream's Warsong: Garrosh buffing all Horde players in Nagrand during the Hero of the Mag'har event.
• [x] K'iru's Song of Victory: This spell is cast by K'iru once all objectives as part of the Shattered Sun Offensive storyline are completed. This buff functions everywhere on the Isle of Quel'Danas and inside Magisters' Terrace.
• [ ] Rallying Cry of the Dragonslayer: Buff players in Stormwind or Orgrimmar for 2 hours
• [x] A'dal's Song of Battle : https://www.wowhead.com/spell=39953/adals-song-of-battle#comments

We can see two types:

1. Spells casted on players at one point which have an aura duration: Rallying Cry of the Dragonslayer & Hellscream's Warsong
2. Area wide buffs without aura duration: Trollbane's Command, Nazgrel's Favor & K'iru's Song of Victory

How can we handle these? Not sure how for the first type but the second could probably be handled with a game_event and reference of it in spell_area.

[Kittnz]

How nost does the wachief blessing https://github.com/lh-server/core/blob/development/src/scripts/kalimdor/orgrimmar/orgrimmar.cpp#L540.

Anyway maybe a player script or we look (loop) for every player in the zone, add the buff or remove it

[kelno]

Hellscream's Warsong and Rallying Cry of the Dragonslayer Should both be done in scripts. The other two (Permanent buffs) are now implemented.