Triggers on enchantments can fire when the attached card is in the wrong zone

[Jetz72]

This is the common issue between #807, #1287, and a few other cases. Either:

• An enchantment is applied to a card, which is then moved or copied with enchantments against the zone flow (e.g. Immortal Prelate, Eternal Army Anomaly); or
• An effect intended to apply an enchantment to a target minion in one zone resolves after the target has moved to a different zone (e.g. Illidan Juggler shenanigans).

Enchantments are always considered to be in play, so any triggered effects on them fire even if the attached card is not, which can lead to bizarre interactions. The devs have stated that this shouldn't happen: https://www.reddit.com/r/hearthstone/comments/9uzkh0/potion_prelate_trade_it_away_draw_and_play_it_end/e98rjcs/

Fun fact, while developing Immortal Prelate these enchantments originally didn't have the restriction that the attached minion had to still be in play. If you stole Immortal Prelate with Potion of Madness and then traded it in, the Immortal Prelate would move from your deck back to your opponent's deck at the end of turn. While hilarious it was also pretty janky, so we added the extra restriction.

However, currently it seems to only be addressed on a per-card basis. This issue can consolidate future cases of this until it's apparent that a general solution is in place.

[Jetz72]

There have been reports of Tekahn's phase 2 power continuing to trigger even though the chosen minion is dead. Since they started in 16.0, I'm pinning this + #1294 as the causes.

https://us.forums.blizzard.com/en/hearthstone/t/curse-of-flame-bug-tot/19594

For some reason, the hero power of Tekahn randomly activated even if the targetted minion dead/not on board. Not sure what could have happen to make this bug, but yeah everything on the board and the heroes started to take 5 damages at the end of my turn.

https://us.forums.blizzard.com/en/hearthstone/t/tekahns-hero-power-in-second-phase/20918

During the second phase versus Tekahn, in Tombs of terror heroic, his hero power is activated even if my minion dies before the opponent’s turn