It does create an interesting tension between needing the card to be binned when needed and just using it to attack or block until it dies
Play with it, and see if this isnt reds version of Harmonize
Given how much space you have to dedicate to creatures in this deck, wanting to play both archetypes would probably lead to a pretty bad representation for both
Once a creature is enchanted by Splinter Twin, it gains the ability to tap, creating a copy of itself that has haste, but must be sacrificed at the end of the turn
Importantly, Danitha already comes with vigilance, lifelink, and trample, so you can save that Sigiled Sword of Valeron and Basilisk Collar for another creature like your Thran Power Suit
The annihilator trigger is particularly punishing in multiplayer, as it dismantles an opponents resources even if they manage to block the damage