The effect would be far too broken if you only had to pay 2 life for it once
The main goal here is to use your commander and your expensive stuff to generate 10 to 15 mana-worth of spells due to all the cascading
Only their abilities can really be disrupted, and only by specific solutions which will only make up a small % of opposing decks
This Dragon's monstrosity effect is costly, but in return, Stormbreath Dragon becomes a sizeable 7/7, and it deals damage to all opponents to keep the pressure up
Nadu, Winged Wisdom What can I say about Nadu, Winged Wisdom that hasnt already been said after this staggeringly pushed 3-drop plagued Commander and decimated Modern with a 59% win rate at Pro Tour Modern Horizons 3
The main things you want to avoid are types that you have a disadvantage against, like effective and especially no-effect type clashes