The COVID-19 pandemic has rapidly increased the use of synchronous online teaching for English-as-a-second-language (ESL) courses. However, there is a scarcity of research on the necessary teaching abilities for online ESL instruction and the advantages of real-time technologies in supporting students' L2 learning. This virtual ethnographic research examines how an ESL teacher utilizes diverse multilingual and multimodal resources to facilitate students' L2 English learning in real-time online tutorials and develops his translanguaging competence over a 10-week period. The analysis, carried out using Multimodal Conversation Analysis and Interpretative Phenomenological Analysis, reveals that the teacher progressively exhibits his capacity to use a variety of multilingual and multimodal tools and to employ different funds of knowledge to support students' English language learning. Consequently, we emphasize the significance of strengthening online language instructors' pedagogical comprehension of translanguaging to enhance their e-Classroom Interactional Competence.