Verbseoul.
하다 verb (adj)
사악하다saakhadavicious

To say vicious politely in the present tense, use 사악해요 (sah-ah-kae-yoh). Below is the full conjugation of 사악하다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
사악해
sah-ah-kae
사악해요
sah-ah-kae-yoh
사악합니다
sah-ah-kahm-nee-dah
Past
사악했어
sah-ah-kae-ssuh
사악했어요
sah-ah-kae-ssuh-yoh
사악했습니다
sah-ah-kae-sseum-nee-dah
Future
사악할 거야
sah-ah-kahl- -guh-yah
사악할 거예요
sah-ah-kahl- -guh-yae-yoh
사악할 겁니다
sah-ah-kahl- -guhm-nee-dah

Other useful forms

Command Polite (세요)
사악하세요
sah-ah-kah-sae-yoh
Suggestion / Let's Polite (요)
사악해요
sah-ah-kae-yoh
Question Polite (요)
사악해요?
sah-ah-kae-yoh-?
Connective “and” — (고)
사악하고
sah-ah-kah-goh
Conditional “if” — (면)
사악하면
sah-ah-kah-myuhn
Noun form — (기)
사악함
sah-ah-kahm