Igni is very useful to continue damaging enemies when you're damaged and can't risk a close fight until you regenerate, or to inflict pain on a whole group. You could still do without it but it would take more time and potions. OTOH I don't know how I would be able to get through without quen, it's a life saver. At level 4-5 it can withstand attacks from multiple strong enemies for a long time and if you power it up it can damage them up to 50% which considerably decreases their dodge abilities. There's nothing like sitting in a middle of a group of wraiths or ifrits and watching them losing health to a point where you can hit them with strong style.@Nekoime: the beast hasn't been changed from vanilla, it's still very easy to stun with aard. Barghests are stronger but with specter oil and group style they go down fast. With Blizzard, Swallow and Tawny Owl it's not much harder than original. Keep away from the fire and the beast itself while dealing with barghest, push it away with aard or retreat if it gets close. Trying to fight with the beast using sword is too hard, it causes too much pain so it's better to keep shooting with aard until it's stunned. Barghest have no defence against knockdown as well so if you see them and the beast charging you together just aard them all, barghest will end up lying on the ground and with luck the beast will be stunned. If it was only knocked down don't get tempted into a sword fight with it, wait for it to get up and aard again or kill some barghest in a meantime.