Sadashiva Pandit is considered a Chaitanya branch of the tree of divine love. He was a resident of Navadwip who participated in the beginnings of the sankirtan movement. When Nityananda Prabhu first arrived in Navadwip, he stayed in his house.
Sadashiva Pandit placed all his hopes at the Lord’s feet. His house was Nityananda Prabhu’s first residence in Navadwip. (Chaitanya Charitamrita 1.10.34) 
He was also one of the Lord’s companions when He engaged in water sports in the Ganges. (In the wallpaper: Shri Krishna Chaitanya, ISKCON Chennai).
Sadashiva Pandit, in whose home Nityananda had previously been domiciled, also went [with the party of Devotees to Jagannath Puri]. (Chaitanya Bhagavat 3.8.19)
In Vrindavan Das Thakur’s Chaitanya Bhagavat, Sadashiva Pandit’s name is included in the list of Devotees who were present in the kirtan in the house of Shrivasa Pandit, along with Gopinath, Jagadisha, Shriman, Shridhara, Vakreshvara, Shrigarbha and Shuklambar. (Chaitanya Bhagavat 2.8.115)
He was also one of the Lord’s companions when He engaged in water sports in the Ganges. He was also one of the first to witness the Lord’s displays of ecstatic love after He returned from Gaya. Mahaprabhu also told him to be present in Shuklambar’s house where He publicly announced the transformation that had taken place.
[The Lord said,] “You [Shriman Pandit] and Sadashiva Pandit should also come tomorrow to Shuklambar’s house. (Chaitanya Bhagavat 2.1.40)
Sadashiva, Murari, Shriman and Shuklambar, and all the Lord’s other devoted followers assembled there. (Chaitanya Bhagavat 2.1.81)
On the same occasion, the Lord Himself revealed to the world how dearly He considered Sadashiva by unveiling His secret pain to him.
“I will reveal all My sadness to you [Shriman Pandit], Sadashiva and Murari Gupta. (Chaitanya Bhagavat 2.1.70)
When Mahaprabhu decided to put on a performance of Vraja lila in the house of Chandrashekhara Acharya, He gave the responsibility for costumes and makeup to Sadashiva and Buddhimanta Khan. Sadashiva was ecstatic to receive this order from the Lord.
The Lord called Buddhimanta Khan and Sadashiva and told them to go immediately to arrange for the actors’ costumes. (Chaitanya Bhagavat 2.18.7)
Overjoyed, Buddhimanta and Sadashiva immediately went home to fulfill the duties given them by the Lord. (Chaitanya Bhagavat 2.18.14)
Here [at the house of Chandrashekhara Acharya], Buddhimanta Khan and Sadashiva Pandit made all kinds of costume arrangements to help Lord Gauranga put on a performance as Lakshmi, so that the entire universe will become intoxicated by the singing of the Holy Names. (Bhakti-ratnakara 12.2903-4)
[Excerpted from “Shri Chaitanya: His Life & Associates” by Shrila Bhakti Ballabh Tirtha Maharaj] 
When Mahaprabhu decided to put on a performance of Vraja lila in the house of Chandrashekhara Acharya, He gave the responsibility for costumes and makeup to Sadashiva and Buddhimanta Khan. Sadashiva was ecstatic to receive this order from the Lord. (In the wallpaper: In the right below Shri Vijaya Gauranga, ISKCON Hungary, New Vraja Dham, Shrimati Lakshmi Devi and in the background image artist putting make up to an actress).