I've put together some that loosely follow this description. These are ones I've read with spunky omegas with an attitude. The softness isnt immediate in these but develops over plot. Hope you find what you're looking for!
http://www.mangago.me/read-manga/unmei_no_kisu_wa_oazuke/
http://www.mangago.me/read-manga/megumi_and_tsugumi/
http://www.mangago.me/read-manga/remnant_kemonohito_omegaverse/
http://www.mangago.me/read-manga/love_is_an_illusion/?av=2
Any omegaverse with a power uke? But when it comes to his alpha he’s all cute and submissive, but can like totally kick your ass.