ARDR is the main coin of the successor blockchain (originally called NXT 2.0) started in early 2018. ARDR were granted to all NXT holders at a specific snapshot.
IGNIS is an "official" token on the ARDR chain which uses the child chain mechanism and is meant to be used for payments, minor tokens, and so on, as its transaction fees are meant to be lower than ARDR's and its transactions can be pruned.
The only other premine was the IGNIS premine in 2018 which was 50% of the supply, from which the majority were sold in a second ICO (for ARDR or NXT, I don't remember well). IGNIS however crashed pretty fast in 2018, so while I guess they made some money with that, it also were not big amounts compared to other ICOs of that time.