XP Stacking w/Pets & Set Bonuses

[Tpfelblatt]

Very nice post. It would be interesting to find out if XP set bonuses can be stacked with elixir bonuses from regular XP elixirs (platinum store/guildhall vendor/elixir kits).

Regarding threat levels, yellow threat level grants approximately 1.29XP/kill. And apparently the threat level can drop when killing a certain amount of enemies.