Bellator
From Tardis Wiki, the free Doctor Who reference
Bellator was a Time Lord.
At the Time Lord Academy, Kenossium was mentored by Bellator, whose lessons taught her how to survive "four-time campaigns and a Time War".
He went to a regeneration tower <---Name is probably incorrect---> to select his next incarnation's form, but it went wrong and he was killed, alongside six other Time Lords who had died in the same way that very day.