The high-z radio-loud AGN (radio galaxies, HzRGs) are hosted by the most massive galaxies living in the centre of protoclusters. They are the best targets to study both energetic (>10^45 erg/s) radiative- and jet-modes feedback in galaxy evolution at the densest cosmic nodes, and a direct view of hosts as type-2 AGN. I have exploited major state-of-the-art IFS: MUSE, JWST/NIRSpec IFU and ALMA to investigate a sample of HzRGs at z~3.5. MUSE characterises the distribution and composition of gaseous halos on 100kpc. JWST reveals AGN radiation+jet disturbed warmed ionised gas kinematic and morphology of ISM. At matched sub-kpc resolution, ALMA targets on cold gas ([CII]158um) and dust. I will show our comprehensive view of CGM gas around these monsters where cluster environments and metal redistribution are seen. JWST data shows that radiative-driven outflow is weak even near the AGN implying jets dominating the feedback. I will also present our new results from these rich dataset where close-by (<15kpc) companions are ubiquitously discovered around these radio AGN with various methods. JWST found rotation signatures of the companions in ionised gas. Rest-frame optical continuum from JWST indicates the existence of stellar population away from AGN hosts. ALMA found off-AGN-center [CII] rotation and dust emission. Our work contributes to galaxy evolution from CGM environments to AGN feedback on ISM and potential interaction from mergers at Cosmic Noon showcasing joint IFU study.