How much of a debuff can you get on casting?

Mercury Angel

Mercury Angel

Avatar of Gwen

Join Date: Apr 2005

Wandering my own road.

Already familiar with the 150% from effects such as dazed/arcane conundrum/migraine, but what about alternate skills such as Nature's Renewal (enchantments and hexes cast within range take 2x longer to cast) and Holy Veil (hexes cast on target ally take 2x longer to cast)?

Would Backfire (base 3 seconds) take 7 1/2 seconds (+150%), 13 1/5 seconds (+350%), or 22 1/2 seconds (+150% x3)?