combo fields
grenade kit #5 is a poison field. So is healing turret normal skill. Pretty sure there’s some more, those are the only 2 I remember at the top of my head.
Bomb 4 is a smoke field. So is the Flame turret overcharge. Elixir gun 5 is a light field. Napalm and I think grenade 2 is a fire field. Toss elixir U is a randomly chosen of three fields. Engineers are great combo field generators, and okay finishers (we have a lot of blasts but you have to nerf your build to use them).
Doing what I can for DB during EU primetime
Engineer has a lot of different types of combo fields available.
Ethereal – 33% with Toss Elixir U (Veil)
Fire – Bomb Kit #2, Flamethrower #4
Ice – Mortar #4
Light – Elixir Gun #5, 33% with Toss Elixir U, Toss Elixir R
Poison – Grenade Kit #5
Smoke – Bomb Kit #4, Flame Turrent overcharge, 33% with Toss Elixir U
Water – Healing Turret overcharge (Regenerating Mist)
A simple online search…
http://wiki.guildwars2.com/wiki/Combo_Field
Engineers are the only profession with all 7 fields. I’m surprise you didn’t claim engineers don’t have Elites at lvl 12.