He has the powerful effect of dealing double damage, making him a strong Tron contender able to get kills with Commander damage
Obviously, Rin and Seri, Inseparable wants you to cast lots of them
If you have a lot of 4+ player Commander games, Coastal Breachs always on cost reduction is going to be pretty attractive, as it requires no setup at all
Whilst being a vehicle version of the cloned creature might seem like a downside, that stops it from being removed by board wipes, or other sorcery-speed effects
If a card successfully defends against an attack, nothing happens - no player takes damage or loses any cards
In a black token deck or a deck that benefits from sacrifice effects, Mukotai Soulripper can actually prove to be some very powerful muscle