Earlier today I was playing halo 5 legendary warzone and killed 2 warden enternals and all I got as a rewared was just a few blue packs! Honestly mytic warzone is more rewarding than legendary plz respond I will be glad to hear your opinon 
A few blue packs? Like, your daily Warzone and Warzone Firefight win packs?
You didnāt get the packs for killing the wardensā¦ You got those as your daily win packs one was for warzone and one was for firefight. Just like if you played an arena game and you or your team won depending on what mode you played you would get a āblueā daily win packā¦ Just like you get a āblueā daily log in pack. The only you get higher xp and rp payouts in mythic vs legendary that is it.
You were rewarded with commendation progress toward warden kills, which gives you a gold pack when you complete level 5. Unless you finished it already.