Sage of Hours and Conclave Sledge-Captain do not have summoning sickness.
Sage of Hours cannot be blocked by an opponent.
Splinter Twin attached to Conclave Sledge-Captain.
Steps
Activate Conclave Sledge-Captain by tapping it, creating a token copy of it with haste.
When the Conclave Sledge-Captain token enters the battlefield, its backup ability triggers three times, all targeting Sage of Hours.
Resolve all Conclave Sledge-Captain triggers, putting three +1/+1 counters on Sage of Hours, and causing it to gain the printed abilities three times until end of turn.
Deal combat damage with Sage of Hours, triggering its abilities granted by Conclave Sledge-Captain three times, putting three +1/+1 counters on Sage of Hours for each damage it dealt.
Activate Sage of Hours by removing all +1/+1 counters from it, causing you to take at least three extra turns after this one.