Services like HIDIVE sometimes offer simulcasts (live streaming of episodes as they air in Japan), but availability can vary.
Many of these sites upload "low-bitrate" versions or "cut" versions that strip away the high-quality animation the series is known for.
You may find versions without proper subtitles or with "hardcoded" ads that ruin the viewing experience. Technical Specs of the OAV
Released in 2018, these episodes focus primarily on Alicia and the final stages of the war. Kuroinu II