Abstract Using Van Allen Probes data (2013–2015), we report that highly oblique chorus waves frequently occur in low‐density regions where fpe/fce≈3 ${f}{text{pe} }/{f}{text{ce} }approx 3$. These waves exhibit an electric‐to‐magnetic energy ratio PE/c2PB>0.5 $sqrt{ {P}{mathrm{E} }/{c}^{2}{P}{mathrm{B} }} > 0.5$, much higher than the typical 65° ${theta }{mathrm{m} } > 65{}^{circ}$ can efficiently scatter relativistic electrons up to 2 MeV near 20° $20{}^{circ}$ equatorial pitch angles primarily via higher‐order resonance. Additionally, HOQE upper‐band chorus θm>50° $left({theta }{mathrm{m} } > 50{}^{circ}right)$ drives strong diffusion of tens of keV electrons at moderate pitch angles. These findings reveal a previously overlooked pathway for MeV electron loss, advancing our understanding of chorus wave‐particle interactions.