(On behalf of the WISSH collaboration) The WISE/SDSS-selected hyper-luminous quasar (WISSH) survey is an extensive multi-band observing program to investigate the role of nuclear activity in SMBH-galaxy self-regulated growth via extended outflows. Our ongoing project is designed to accurately probe the relationship between nuclear and host galaxy ISM properties in a large sample of ~90 quasars at the brightest end of the AGN luminosity function (log LBol > 47.3) and at the peak of their number density (z~2.5-3.5)We will report on the discovery of highly accreting (0.3-3Ledd), ten billion solar masses SMBHs being able to produce very powerful (up to ~ 4% of L_bol) ionized outflows and accretion disk windsThe impact of AGN-driven feedback on their host galaxies will be also discussed.