
Not sure where you're getting 'hemp' from...
「今のが魔力変換速度100%…」 is "That (just now) was 100% magic conversion speed..."
The other page is roughly:
"This roar is similar to your magic bullet"
"It has a cast time of 1 second"
"Only Snow Yetis can use it, so with them you have to watch out for it" (lit: outside of Snow Yetis it can't be used, but if it's a Snow Yeti, they'll use it on you)
"It's magic that you could have prevented if you knew about it"
Also, the lines starting with 「あれは魔法を行使してるよ」 are saying "That's magic it's using. It's earth-elemental magic. It boosts its physical abilities for 3 minutes."