Helvie rhymes with:
helvey, castellvi, elvie, elvy, helvey, melvie, selvey, alvey, calvi, castellvi, elvie, elvy, falvey, helvey, hulvey, malvie, melvie, ogilvie, ogilvy, olvey, salvi, selvey, silvey, silvi, silvie, stalvey, sylvie
Helvie sounds like:
halebopp, halevi, half, halfway, halifa, halve, helaba, helf, helluva, help, helvey, hilb, holub, hulvey